Option to disable all tag processing;  Minor bug fix to QCBORDecode_GetDecimalFraction() 

This allows disabling of all tag decoding saving about 400 bytes of object code (a lot!).

This also fixes a bug where QCBORDecode_GetDecimalFraction() and
QCBORDecode_GetDecimalFractionBig() would fail on input CBOR that is not a tag when it should succeed.



* Check point work on disabling tags

* Check point tag disable

* Checkpoint work on disabling tags

* check point

* More tests are passing

* Check point ; down to only 3 tests not passing

* all tests passing

* documentation fixes

* minor tidying

* more tidiness

* More documentation

* Check point -- more tidiness

* Check point new mant/exp tests

* main source is probably done; more testing to do

* Documentation fix

* Improve testing of mantissa and exponent a lot

* Final clean up

Co-authored-by: Laurence Lundblade <lgl@securitytheory.com>
diff --git a/README.md b/README.md
index d26c56c..28e3b14 100644
--- a/README.md
+++ b/README.md
@@ -324,9 +324,9 @@
 
     |               | smallest | largest |  
     |---------------|----------|---------|
-    | encode only   |      850 |    2100 |
-    | decode only   |     2000 |   13300 |
-    | combined      |     2850 |   15500 |
+    | encode only   |      900 |    2100 |
+    | decode only   |     1550 |   13300 |
+    | combined      |     2450 |   15500 |
     
  From the table above, one can see that the amount of code pulled in
  from the QCBOR library varies a lot, ranging from 1KB to 15KB.  The
@@ -381,6 +381,7 @@
     | QCBOR_DISABLE_EXP_AND_MANTISSA          |   400 | 
     | QCBOR_DISABLE_PREFERRED_FLOAT           |   900 | 
     | QCBOR_DISABLE_FLOAT_HW_USE              |    50 | 
+    | QCBOR_DISABLE_TAGS                      |   400 | 
     | USEFULBUF_DISABLE_ALL_FLOAT             |   950 | 
 
 QCBOR_DISABLE_ENCODE_USAGE_GUARDS affects encoding only.  It doesn't
@@ -409,12 +410,17 @@
 when an indefinite-length map or array arrives for decoding.
 
 QCBOR_DISABLE_UNCOMMON_TAGS disables the decoding of explicit tags for
-base 64, regex, UUID and MIME data. This just disabled the automatic
+base 64, regex, UUID and MIME data. This just disables the automatic
 recognition of these from a major type 6 tag.
 
 QCBOR_DISABLE_EXP_AND_MANTISSA disables the decoding of decimal
 fractions and big floats.
 
+QCBOR_DISABLE_TAGS disables all decoding of CBOR tags. If the input has
+a single tag, the error is unrecoverable so it is suitable only for protocols that 
+have no tags. "Borrowed" tag content formats (e.g. an epoch-based date
+without the tag number), can still be processed.
+
 See the discussion above on floating-point.
 
  ### Size of spiffy decode
diff --git a/inc/qcbor/qcbor_common.h b/inc/qcbor/qcbor_common.h
index e9f9a7c..127537d 100644
--- a/inc/qcbor/qcbor_common.h
+++ b/inc/qcbor/qcbor_common.h
@@ -468,6 +468,10 @@
        indefinite length map or array in the input CBOR. */
    QCBOR_ERR_INDEF_LEN_ARRAYS_DISABLED = 50,
 
+   /** All decoding of tags (major type 6) has been disabled and a tag
+       occurred in the decode input. */
+   QCBOR_ERR_TAGS_DISABLED = 51,
+
 #define QCBOR_END_OF_UNRECOVERABLE_DECODE_ERRORS 59
 
    /** More than @ref QCBOR_MAX_TAGS_PER_ITEM tags encountered for a
diff --git a/inc/qcbor/qcbor_decode.h b/inc/qcbor/qcbor_decode.h
index 65eff4c..bf30e6d 100644
--- a/inc/qcbor/qcbor_decode.h
+++ b/inc/qcbor/qcbor_decode.h
@@ -162,6 +162,23 @@
  * item being sought, in which case the unrecoverable error will be
  * returned. Unrecoverable errors are those indicated by
  * QCBORDecode_IsUnrecoverableError().
+ *
+ * @anchor Disabilng-Tag-Decoding
+ * # Disabilng Tag Decoding
+ *
+ * If QCBOR_DISABLE_TAGS is defined, all code for decoding tags will
+ * be omitted reducing the core decoder, QCBORDecode_VGetNext(), by
+ * about 400 bytes. If a tag number is encountered in the decoder
+ * input the unrecoverable error @ref QCBOR_ERR_TAGS_DISABLED will be
+ * returned.  No input with tags can be decoded.
+ *
+ * Decode functions like QCBORDecode_GetEpochDate() and
+ * QCBORDecode_GetDecimalFraction() that can decode the tag content
+ * even if the tag number is absent are still available.  Typically
+ * they won't be linked in because of dead stripping. The 
+ * @c uTagRequirement parameter has no effect, but if it is
+ * @ref QCBOR_TAG_REQUIREMENT_TAG, @ref QCBOR_ERR_TAGS_DISABLED
+ * will be set.
  */
 
 /**
@@ -481,6 +498,7 @@
       uint64_t    uint64;
    } label;
 
+#ifndef QCBOR_DISABLE_TAGS
    /**
     * The tags numbers for which the item is the tag content.  Tags
     * nest, so index 0 in the array is the tag on the data item
@@ -502,6 +520,7 @@
     * having to reference this array. Also see @ref Tags-Overview.
     */
    uint16_t uTags[QCBOR_MAX_TAGS_PER_ITEM];
+#endif
 
 } QCBORItem;
 
diff --git a/inc/qcbor/qcbor_spiffy_decode.h b/inc/qcbor/qcbor_spiffy_decode.h
index 9103782..0faddc3 100644
--- a/inc/qcbor/qcbor_spiffy_decode.h
+++ b/inc/qcbor/qcbor_spiffy_decode.h
@@ -88,7 +88,7 @@
  ## Tag Usage
 
  Data types beyond the basic CBOR types of numbers, strings, maps and
- arrays are called tags. The main registry of these new types is in in
+ arrays are called tags. The main registry of these new types is in
  the IANA CBOR tags registry. These new types may be simple such a
  number that is to be interpreted as a date, or of moderate complexity
  such as defining a decimal fraction that is an array containing a
@@ -296,6 +296,12 @@
  See also QCBORDecode_GetInt64ConvertAll() which does some of these
  conversions, but links in much less object code. See also
  QCBORDecode_GetUInt64ConvertAll().
+
+ This relies on CBOR tags to identify big numbers, decimal fractions
+ and big floats. It will not attempt to decode non-tag CBOR that might
+ be one of these.  (If QCBOR_DISABLE_TAGS is set, this is effectively
+ the same as QCBORDecode_GetInt64Convert() because all the additional
+ number types this decodes are tags).
  */
 void QCBORDecode_GetInt64ConvertAll(QCBORDecodeContext *pCtx,
                                     uint32_t            uConvertTypes,
@@ -1210,6 +1216,10 @@
  See also @ref CBOR_TAG_DECIMAL_FRACTION,
  QCBOREncode_AddDecimalFraction(), @ref QCBOR_TYPE_DECIMAL_FRACTION
  and QCBORDecode_GetDecimalFractionBig().
+
+ If QCBOR_DISABLE_TAGS is set, the only input this will decode is
+ an array of two integers. It will set an error if the the array is preceded
+ by by a tag number or if the mantissa is a big number.
 */
 void QCBORDecode_GetDecimalFraction(QCBORDecodeContext *pCtx,
                                     uint8_t             uTagRequirement,
@@ -1297,6 +1307,10 @@
 
      mantissa * ( 2 ** exponent )
 
+ If the mantissa is a tag that is a positive or negative big number,
+ this will attempt to fit it into the int64_t that @c pnMantissa is
+ and set an overflow error if it doesn't fit.
+
  See also QCBORDecode_GetInt64ConvertAll(),
  QCBORDecode_GetUInt64ConvertAll() and
  QCBORDecode_GetDoubleConvertAll() which can convert big floats.
@@ -1979,21 +1993,28 @@
 
 
 
-// Semi private (this may change in the future)
 #define QCBOR_TAGSPEC_NUM_TYPES 4
-/* Improvement:  Carefully understand what compilers do with this,
-particularly initialization and see if it can be optimized so
-there is less code and maybe so it can be smaller. */
+/* Semi-private data structure (which might change).
+ *
+ * See CheckTagRequirement() which uses this to check the type of a
+ * item to be decoded as a tag or tag content.
+ *
+ * Improvement: Carefully understand what compilers do with this,
+ * particularly initialization and see if it can be optimized so there
+ * is less code and maybe so it can be smaller.
+ */
 typedef struct {
    /* One of QCBOR_TAGSPEC_MATCH_xxx */
    uint8_t uTagRequirement;
-   /* The tagged type translated into QCBOR_TYPE_XXX. Used to match explicit
-      tagging */
+   /* The tagged type translated into QCBOR_TYPE_XXX. Used to match
+    * explicit tagging */
    uint8_t uTaggedTypes[QCBOR_TAGSPEC_NUM_TYPES];
-   /* The types of the content, which are used to match implicit tagging */
+   /* The types of the content, which are used to match implicit
+    * tagging */
    uint8_t uAllowedContentTypes[QCBOR_TAGSPEC_NUM_TYPES];
 } TagSpecification;
 
+
 // Semi private
 void QCBORDecode_GetTaggedStringInternal(QCBORDecodeContext *pMe,
                                          TagSpecification    TagSpec,
diff --git a/src/qcbor_decode.c b/src/qcbor_decode.c
index 46c4f12..841f49a 100644
--- a/src/qcbor_decode.c
+++ b/src/qcbor_decode.c
@@ -1163,12 +1163,16 @@
          break;
 
       case CBOR_MAJOR_TYPE_TAG: /* Major type 6, tag numbers */
+#ifndef QCBOR_DISABLE_TAGS
          if(nAdditionalInfo == LEN_IS_INDEFINITE) {
             uReturn = QCBOR_ERR_BAD_INT;
          } else {
             pDecodedItem->val.uTagV = uArgument;
             pDecodedItem->uDataType = QCBOR_TYPE_TAG;
          }
+#else /* QCBOR_DISABLE_TAGS */
+         uReturn = QCBOR_ERR_TAGS_DISABLED;
+#endif /* QCBOR_DISABLE_TAGS */
          break;
 
       case CBOR_MAJOR_TYPE_SIMPLE:
@@ -1347,6 +1351,7 @@
 }
 
 
+#ifndef QCBOR_DISABLE_TAGS
 /**
  * @brief This converts a tag number to a shorter mapped value for storage.
  *
@@ -1421,6 +1426,7 @@
       return pMe->auMappedTags[uIndex];
    }
 }
+#endif /* QCBOR_DISABLE_TAGS */
 
 
 /**
@@ -1450,6 +1456,7 @@
 static QCBORError
 QCBORDecode_GetNextTagNumber(QCBORDecodeContext *pMe, QCBORItem *pDecodedItem)
 {
+#ifndef QCBOR_DISABLE_TAGS
    /* Accummulate the tags from multiple items here and then copy them
     * into the last item, the non-tag item.
     */
@@ -1508,8 +1515,13 @@
 
 Done:
    return uReturn;
-}
 
+#else /* QCBOR_DISABLE_TAGS */
+
+   return QCBORDecode_GetNextFullString(pMe, pDecodedItem);
+
+#endif /* QCBOR_DISABLE_TAGS */
+}
 
 /**
  * @brief Combine a map entry label and value into one item (decode layer 3).
@@ -1900,6 +1912,7 @@
 }
 
 
+#ifndef QCBOR_DISABLE_TAGS
 /**
  * @brief Shift 0th tag out of the tag list.
  *
@@ -1916,6 +1929,7 @@
    pDecodedItem->uTags[QCBOR_MAX_TAGS_PER_ITEM-1] = CBOR_TAG_INVALID16;
 }
 
+#endif /* QCBOR_DISABLE_TAGS */
 
 /**
  * @brief Convert different epoch date formats in to the QCBOR epoch date format
@@ -2074,6 +2088,18 @@
 
 
 #ifndef QCBOR_DISABLE_EXP_AND_MANTISSA
+
+/* Forward declaration is necessary for
+ * QCBORDecode_MantissaAndExponent().  to be able to decode bignum
+ * tags in the mantissa. If the mantissa is a decimal fraction or big
+ * float in error, this will result in a recurive call to
+ * QCBORDecode_MantissaAndExponent(), but the recursion will unwined
+ * correctly and the correct error is returned.
+ */
+static QCBORError
+QCBORDecode_GetNextTagContent(QCBORDecodeContext *pMe, QCBORItem *pDecodedItem);
+
+
 /**
  * @brief Decode decimal fractions and big floats.
  *
@@ -2086,14 +2112,19 @@
  * @returns  Decoding errors from getting primitive data items or
  *           \ref QCBOR_ERR_BAD_EXP_AND_MANTISSA.
  *
- * When called pDecodedItem must be the array that is tagged as a big
- * float or decimal fraction, the array that has the two members, the
+ * When called pDecodedItem must be the array with two members, the
  * exponent and mantissa.
  *
  * This will fetch and decode the exponent and mantissa and put the
  * result back into pDecodedItem.
+ *
+ * This does no checking or processing of tag numbers. That is to be
+ * done by the code that calls this.
+ *
+ * This stuffs the type of the mantissa into pDecodedItem with the expectation
+ * the caller will process it.
  */
-static inline QCBORError
+static QCBORError
 QCBORDecode_MantissaAndExponent(QCBORDecodeContext *pMe, QCBORItem *pDecodedItem)
 {
    QCBORError uReturn;
@@ -2105,16 +2136,12 @@
    }
 
    /* A check for pDecodedItem->val.uCount == 2 would work for
-    * definite-length arrays, but not for indefnite.  Instead remember
+    * definite-length arrays, but not for indefinite.  Instead remember
     * the nesting level the two integers must be at, which is one
     * deeper than that of the array.
     */
    const int nNestLevel = pDecodedItem->uNestingLevel + 1;
 
-   /* --- Which is it, decimal fraction or a bigfloat? --- */
-   const bool bIsTaggedDecimalFraction = QCBORDecode_IsTagged(pMe, pDecodedItem, CBOR_TAG_DECIMAL_FRACTION);
-   pDecodedItem->uDataType = bIsTaggedDecimalFraction ? QCBOR_TYPE_DECIMAL_FRACTION : QCBOR_TYPE_BIGFLOAT;
-
    /* --- Get the exponent --- */
    QCBORItem exponentItem;
    uReturn = QCBORDecode_GetNextMapOrArray(pMe, &exponentItem);
@@ -2142,7 +2169,7 @@
 
    /* --- Get the mantissa --- */
    QCBORItem mantissaItem;
-   uReturn = QCBORDecode_GetNextWithTags(pMe, &mantissaItem, NULL);
+   uReturn = QCBORDecode_GetNextTagContent(pMe, &mantissaItem);
    if(uReturn != QCBOR_SUCCESS) {
       goto Done;
    }
@@ -2151,6 +2178,9 @@
       uReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
       goto Done;
    }
+   /* Stuff the mantissa data type into the item to send it up to the
+    * the next level. */
+   pDecodedItem->uDataType = mantissaItem.uDataType;
    if(mantissaItem.uDataType == QCBOR_TYPE_INT64) {
       /* Data arriving as an unsigned int < INT64_MAX has been
        * converted to QCBOR_TYPE_INT64 and thus handled here. This is
@@ -2159,14 +2189,16 @@
        * and thus an error that will get handled in an else below.
        */
       pDecodedItem->val.expAndMantissa.Mantissa.nInt = mantissaItem.val.int64;
+#ifndef QCBOR_DISABLE_TAGS
+      /* With tags fully disabled a big number mantissa will error out
+       * in the call to QCBORDecode_GetNextWithTags() because it has
+       * a tag number.
+       */
    }  else if(mantissaItem.uDataType == QCBOR_TYPE_POSBIGNUM ||
               mantissaItem.uDataType == QCBOR_TYPE_NEGBIGNUM) {
       /* Got a good big num mantissa */
       pDecodedItem->val.expAndMantissa.Mantissa.bigNum = mantissaItem.val.bigNum;
-      /* Depends on numbering of QCBOR_TYPE_XXX */
-      pDecodedItem->uDataType = (uint8_t)(pDecodedItem->uDataType +
-                                          mantissaItem.uDataType - QCBOR_TYPE_POSBIGNUM +
-                                          1);
+#endif /* QCBOR_DISABLE_TAGS */
    } else {
       /* Wrong type of mantissa or a QCBOR_TYPE_UINT64 > INT64_MAX */
       uReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
@@ -2176,6 +2208,7 @@
    /* --- Check that array only has the two numbers --- */
    if(mantissaItem.uNextNestLevel == nNestLevel) {
       /* Extra items in the decimal fraction / big float */
+      /* Improvement: this should probably be an unrecoverable error. */
       uReturn = QCBOR_ERR_BAD_EXP_AND_MANTISSA;
       goto Done;
    }
@@ -2187,6 +2220,8 @@
 #endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
 
 
+#ifndef QCBOR_DISABLE_TAGS
+
 #ifndef QCBOR_DISABLE_UNCOMMON_TAGS
 /**
  * @brief Decode the MIME type tag
@@ -2215,7 +2250,6 @@
 }
 #endif /* QCBOR_DISABLE_UNCOMMON_TAGS */
 
-
 /**
  * Table of CBOR tags whose content is either a text string or a byte
  * string. The table maps the CBOR tag to the QCBOR type. The high-bit
@@ -2303,6 +2337,31 @@
    pDecodedItem->uDataType = (uint8_t)(uQCBORType & QCBOR_TYPE_MASK);
    return QCBOR_SUCCESS;
 }
+#endif /* QCBOR_DISABLE_TAGS */
+
+
+#ifndef QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA
+/*
+ * This returns the QCBOR_TYPE for a mantissa and exponent.
+
+Called in one context where there is always a tag
+
+ Called in another context where there might be a tag or the caller might say what they are expecting.
+
+ 6 possible outputs
+ */
+static inline uint8_t
+MantissaExponentDataType(const uint16_t uTagToProcess, const QCBORItem *pDecodedItem)
+{
+   uint8_t uBase = uTagToProcess == CBOR_TAG_DECIMAL_FRACTION ?
+                                       QCBOR_TYPE_DECIMAL_FRACTION :
+                                       QCBOR_TYPE_BIGFLOAT;
+   if(pDecodedItem->uDataType != QCBOR_TYPE_INT64) {
+      uBase = (uint8_t)(uBase + pDecodedItem->uDataType - QCBOR_TYPE_POSBIGNUM + 1);
+   }
+   return uBase;
+}
+#endif /* QCBOR_CONFIG_DISABLE_EXP_AND_MANTISSA */
 
 
 /**
@@ -2328,6 +2387,7 @@
       goto Done;
    }
 
+#ifndef QCBOR_DISABLE_TAGS
    /* When there are no tag numbers for the item, this exits first
     * thing and effectively does nothing.
     *
@@ -2357,6 +2417,9 @@
       } else if(uTagToProcess == CBOR_TAG_DECIMAL_FRACTION ||
                 uTagToProcess == CBOR_TAG_BIGFLOAT) {
          uReturn = QCBORDecode_MantissaAndExponent(pMe, pDecodedItem);
+         /* --- Which is it, decimal fraction or a bigfloat? --- */
+         pDecodedItem->uDataType = MantissaExponentDataType(uTagToProcess, pDecodedItem);
+
 #endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
 #ifndef QCBOR_DISABLE_UNCOMMON_TAGS
       } else if(uTagToProcess == CBOR_TAG_MIME ||
@@ -2388,6 +2451,7 @@
        */
       ShiftTags(pDecodedItem);
    }
+#endif /* QCBOR_DISABLE_TAGS */
 
 Done:
    return uReturn;
@@ -2463,6 +2527,8 @@
                             QCBORItem          *pDecodedItem,
                             QCBORTagListOut    *pTags)
 {
+#ifndef QCBOR_DISABLE_TAGS
+
    QCBORError uReturn;
 
    uReturn = QCBORDecode_GetNext(pMe, pDecodedItem);
@@ -2486,6 +2552,13 @@
    }
 
    return QCBOR_SUCCESS;
+
+#else /* QCBOR_DISABLE_TAGS */
+   (void)pMe;
+   (void)pDecodedItem;
+   (void)pTags;
+   return QCBOR_ERR_TAGS_DISABLED;
+#endif /* QCBOR_DISABLE_TAGS */
 }
 
 
@@ -2496,6 +2569,7 @@
                           const QCBORItem   *pItem,
                           uint64_t           uTag)
 {
+#ifndef QCBOR_DISABLE_TAGS
    for(unsigned uTagIndex = 0; uTagIndex < QCBOR_MAX_TAGS_PER_ITEM; uTagIndex++) {
       if(pItem->uTags[uTagIndex] == CBOR_TAG_INVALID16) {
          break;
@@ -2504,6 +2578,11 @@
          return true;
       }
    }
+#else /* QCBOR_TAGS_DISABLED */
+   (void)pMe;
+   (void)pItem;
+   (void)uTag;
+#endif /* QCBOR_TAGS_DISABLED */
 
    return false;
 }
@@ -2564,6 +2643,7 @@
                                const QCBORItem    *pItem,
                                uint32_t            uIndex)
 {
+#ifndef QCBOR_DISABLE_TAGS
    if(pItem->uDataType == QCBOR_TYPE_NONE) {
       return CBOR_TAG_INVALID64;
    }
@@ -2572,6 +2652,13 @@
    } else {
       return UnMapTagNumber(pMe, pItem->uTags[uIndex]);
    }
+#else /* QCBOR_DISABLE_TAGS */
+   (void)pMe;
+   (void)pItem;
+   (void)uIndex;
+
+   return CBOR_TAG_INVALID64;
+#endif /* QCBOR_DISABLE_TAGS */
 }
 
 
@@ -2581,6 +2668,8 @@
 uint64_t QCBORDecode_GetNthTagOfLast(const QCBORDecodeContext *pMe,
                                      uint32_t                  uIndex)
 {
+#ifndef QCBOR_DISABLE_TAGS
+
    if(pMe->uLastError != QCBOR_SUCCESS) {
       return CBOR_TAG_INVALID64;
    }
@@ -2589,6 +2678,12 @@
    } else {
       return UnMapTagNumber(pMe, pMe->uLastTags[uIndex]);
    }
+#else /* QCBOR_DISABLE_TAGS */
+   (void)pMe;
+   (void)uIndex;
+
+   return CBOR_TAG_INVALID64;
+#endif /* QCBOR_DISABLE_TAGS */
 }
 
 
@@ -2784,9 +2879,15 @@
 
 
 
-static inline void CopyTags(QCBORDecodeContext *pMe, const QCBORItem *pItem)
+static inline void
+CopyTags(QCBORDecodeContext *pMe, const QCBORItem *pItem)
 {
+#ifndef QCBOR_DISABLE_TAGS
    memcpy(pMe->uLastTags, pItem->uTags, sizeof(pItem->uTags));
+#else
+   (void)pMe;
+   (void)pItem;
+#endif
 }
 
 
@@ -3224,7 +3325,6 @@
 }
 
 
-
 static QCBORError
 CheckTypeList(int uDataType, const uint8_t puTypeList[QCBOR_TAGSPEC_NUM_TYPES])
 {
@@ -3238,30 +3338,47 @@
 
 
 /**
- @param[in] TagSpec  Specification for matching tags.
- @param[in] pItem    The item to check.
-
- @retval QCBOR_SUCCESS   \c uDataType is allowed by @c TagSpec
- @retval QCBOR_ERR_UNEXPECTED_TYPE \c uDataType is not allowed by @c TagSpec
-
- The data type must be one of the QCBOR_TYPEs, not the IETF CBOR Registered
- tag value.
+ * Match a tag/type specification against the type of the item.
+ *
+ * @param[in] TagSpec  Specification for matching tags.
+ * @param[in] pItem    The item to check.
+ *
+ * @retval QCBOR_SUCCESS   \c uDataType is allowed by @c TagSpec
+ * @retval QCBOR_ERR_UNEXPECTED_TYPE \c uDataType is not allowed by @c TagSpec
+ *
+ * This checks the item data type of untagged items as well as of
+ * tagged items against a specification to see if decoding should
+ * proceed.
+ *
+ * This relies on the automatic tag decoding done by QCBOR that turns
+ * tag numbers into particular QCBOR_TYPEs so there is no actual
+ * comparsion of tag numbers, just of QCBOR_TYPEs.
+ *
+ * This checks the data item type as possibly representing the tag
+ * number or as the tag content type.
+ *
+ * If QCBOR_DISABLE_TAGS is #defined,  this primarily checks the item
+ * data type against the allowed tag content types. It will also error out
+ * if the caller tries to require a tag because there is no way that can
+ * ever be fulfilled.
  */
 static QCBORError
 CheckTagRequirement(const TagSpecification TagSpec, const QCBORItem *pItem)
 {
+   const int nItemType = pItem->uDataType;
+   const int nTagReq = TagSpec.uTagRequirement & ~QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS;
+
+#ifndef QCBOR_DISABLE_TAGS
    if(!(TagSpec.uTagRequirement & QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS) &&
       pItem->uTags[0] != CBOR_TAG_INVALID16) {
       /* There are tags that QCBOR couldn't process on this item and
-       the caller has told us there should not be. */
+       * the caller has told us there should not be.
+       */
       return QCBOR_ERR_UNEXPECTED_TYPE;
    }
 
-   const int nTagReq = TagSpec.uTagRequirement & ~QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS;
-   const int nItemType = pItem->uDataType;
-
    if(nTagReq == QCBOR_TAG_REQUIREMENT_TAG) {
-      // Must match the tag and only the tag
+      /* Must match the tag number and only the tag */
       return CheckTypeList(nItemType, TagSpec.uTaggedTypes);
    }
 
@@ -3272,26 +3389,35 @@
 
    if(nTagReq == QCBOR_TAG_REQUIREMENT_NOT_A_TAG) {
       /* Must match the content type and only the content type.
-       There was no match just above so it is a fail. */
+       * There was no match just above so it is a fail. */
       return QCBOR_ERR_UNEXPECTED_TYPE;
    }
 
-   /* If here it can match either the tag or the content
-    and it hasn't matched the content, so the end
-    result is whether it matches the tag. This is
-    also the case that the CBOR standard discourages. */
+   /* QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG: If here it can match either the tag or the content
+    * and it hasn't matched the content, so the end
+    * result is whether it matches the tag. This is
+    * the tag optional case that the CBOR standard discourages.
+    */
 
    return CheckTypeList(nItemType, TagSpec.uTaggedTypes);
-}
 
+#else /* QCBOR_DISABLE_TAGS */
+   if(nTagReq == QCBOR_TAG_REQUIREMENT_TAG) {
+      return QCBOR_ERR_UNEXPECTED_TYPE;
+   }
+
+   return CheckTypeList(nItemType, TagSpec.uAllowedContentTypes);
+
+#endif /* QCBOR_DISABLE_TAGS */
+}
 
 
 // This could be semi-private if need be
 static inline
-void QCBORDecode_GetTaggedItemInMapN(QCBORDecodeContext *pMe,
-                                     int64_t             nLabel,
-                                     TagSpecification    TagSpec,
-                                     QCBORItem          *pItem)
+void QCBORDecode_GetTaggedItemInMapN(QCBORDecodeContext    *pMe,
+                                     const int64_t          nLabel,
+                                     const TagSpecification TagSpec,
+                                     QCBORItem             *pItem)
 {
    QCBORDecode_GetItemInMapN(pMe, nLabel, QCBOR_TYPE_ANY, pItem);
    if(pMe->uLastError != QCBOR_SUCCESS) {
@@ -3304,10 +3430,10 @@
 
 // This could be semi-private if need be
 static inline
-void QCBORDecode_GetTaggedItemInMapSZ(QCBORDecodeContext *pMe,
-                                     const char          *szLabel,
-                                     TagSpecification    TagSpec,
-                                     QCBORItem          *pItem)
+void QCBORDecode_GetTaggedItemInMapSZ(QCBORDecodeContext    *pMe,
+                                     const char             *szLabel,
+                                     const TagSpecification  TagSpec,
+                                     QCBORItem              *pItem)
 {
    QCBORDecode_GetItemInMapSZ(pMe, szLabel, QCBOR_TYPE_ANY, pItem);
    if(pMe->uLastError != QCBOR_SUCCESS) {
@@ -3321,7 +3447,7 @@
 void QCBORDecode_GetTaggedStringInMapN(QCBORDecodeContext *pMe,
                                        int64_t             nLabel,
                                        TagSpecification    TagSpec,
-                                       UsefulBufC          *pString)
+                                       UsefulBufC         *pString)
 {
    QCBORItem Item;
    QCBORDecode_GetTaggedItemInMapN(pMe, nLabel, TagSpec, &Item);
@@ -3631,10 +3757,11 @@
 
 
 
-static QCBORError InternalEnterBstrWrapped(QCBORDecodeContext *pMe,
-                                           const QCBORItem    *pItem,
-                                           uint8_t             uTagRequirement,
-                                           UsefulBufC         *pBstr)
+static QCBORError
+InternalEnterBstrWrapped(QCBORDecodeContext *pMe,
+                         const QCBORItem    *pItem,
+                         const uint8_t       uTagRequirement,
+                         UsefulBufC         *pBstr)
 {
    if(pBstr) {
       *pBstr = NULLUsefulBufC;
@@ -3875,7 +4002,7 @@
 
 static void ProcessEpochDate(QCBORDecodeContext *pMe,
                              QCBORItem           *pItem,
-                             uint8_t              uTagRequirement,
+                             const uint8_t        uTagRequirement,
                              int64_t             *pnTime)
 {
    if(pMe->uLastError != QCBOR_SUCCESS) {
@@ -4054,13 +4181,16 @@
 
 
 
-
-void QCBORDecode_GetTaggedStringInternal(QCBORDecodeContext *pMe,
-                                         TagSpecification    TagSpec,
-                                         UsefulBufC         *pBstr)
+/*
+ * @brief Get a string that matches the type/tag specification.
+ */
+void
+QCBORDecode_GetTaggedStringInternal(QCBORDecodeContext     *pMe,
+                                    const TagSpecification  TagSpec,
+                                    UsefulBufC             *pBstr)
 {
    if(pMe->uLastError != QCBOR_SUCCESS) {
-      // Already in error state, do nothing
+      /* Already in error state, do nothing */
       return;
    }
 
@@ -4085,10 +4215,11 @@
 
 
 
-static QCBORError ProcessBigNum(uint8_t          uTagRequirement,
-                                const QCBORItem *pItem,
-                                UsefulBufC      *pValue,
-                                bool            *pbIsNegative)
+static QCBORError
+ProcessBigNum(const uint8_t   uTagRequirement,
+             const QCBORItem *pItem,
+             UsefulBufC      *pValue,
+             bool            *pbIsNegative)
 {
    const TagSpecification TagSpec =
    {
@@ -4179,10 +4310,11 @@
 
 
 // Semi private
-QCBORError QCBORDecode_GetMIMEInternal(uint8_t     uTagRequirement,
-                                       const       QCBORItem *pItem,
-                                       UsefulBufC *pMessage,
-                                       bool       *pbIsTag257)
+QCBORError
+QCBORDecode_GetMIMEInternal(const uint8_t     uTagRequirement,
+                            const QCBORItem  *pItem,
+                            UsefulBufC       *pMessage,
+                            bool             *pbIsTag257)
 {
    const TagSpecification TagSpecText =
       {
@@ -5469,38 +5601,105 @@
 }
 
 
-static QCBORError MantissaAndExponentTypeHandler(QCBORDecodeContext *pMe,
-                                                 TagSpecification    TagSpec,
-                                                 QCBORItem          *pItem)
+/**
+ * @brief Check and/or complete mantissa and exponent item.
+ *
+ * @param[in] pMe        The decoder context
+ * @param[in] TagSpec    Expected type(s)
+ * @param[in,out] pItem  See below
+ *
+ * This is for decimal fractions and big floats, both of which are a
+ * mantissa and exponent.
+ *
+ * The input item is either a fully decoded decimal faction or big
+ * float, or a just the decoded first item of a decimal fraction or
+ * big float.
+ *
+ * On output, the item is always a fully decoded decimal fraction or
+ * big float.
+ *
+ * This errors out if the input type does not meet the TagSpec.
+ */
+// TODO: document and see tests for the bug that was fixed by this rewrite
+static QCBORError
+MantissaAndExponentTypeHandler(QCBORDecodeContext     *pMe,
+                               const TagSpecification  TagSpec,
+                               QCBORItem              *pItem)
 {
    QCBORError uErr;
-   // Loops runs at most 1.5 times. Making it a loop saves object code.
-   while(1) {
-      uErr = CheckTagRequirement(TagSpec, pItem);
-      if(uErr != QCBOR_SUCCESS) {
-         goto Done;
-      }
 
-      if(pItem->uDataType != QCBOR_TYPE_ARRAY) {
-         break; // Successful exit. Moving on to finish decoding.
-      }
+   /* pItem could either be an auto-decoded mantissa and exponent or
+    * the opening array of an undecoded mantissa and exponent. This
+    * check will succeed on either, but doesn't say which it was.
+    */
+   uErr = CheckTagRequirement(TagSpec, pItem);
+   if(uErr != QCBOR_SUCCESS) {
+      goto Done;
+   }
 
-      // The item is an array, which means an undecoded
-      // mantissa and exponent, so decode it. It will then
-      // have a different type and exit the loop if.
+   if(pItem->uDataType == QCBOR_TYPE_ARRAY) {
+      /* The item is an array, which means is is an undecoded mantissa
+       * and exponent. This call consumes the items in the array and
+       * results in a decoded mantissa and exponent in pItem. This is
+       * the case where there was no tag.
+       */
       uErr = QCBORDecode_MantissaAndExponent(pMe, pItem);
       if(uErr != QCBOR_SUCCESS) {
          goto Done;
       }
 
-      // Second time around, the type must match.
-      TagSpec.uTagRequirement = QCBOR_TAG_REQUIREMENT_TAG;
+      /* The above decode didn't determine whether it is a decimal
+       * fraction or big num. Which of these two depends on what the
+       * caller wants it decoded as since there is no tag, so fish the
+       * type out of the TagSpec. */
+      pItem->uDataType = MantissaExponentDataType(TagSpec.uTaggedTypes[0], pItem);
+
+      /* No need to check the type again. All that we need to know was
+       * that it decoded correctly as a mantissa and exponent. The
+       * QCBOR type is set out by what was requested.
+       */
    }
+
+   /* If the item was not an array and the check passed, then
+    * it is a fully decoded big float or decimal fraction and
+    * matches what is requested.
+    */
+
 Done:
    return uErr;
 }
 
 
+/* Some notes from the work to disable tags.
+ *
+ * The API for big floats and decimal fractions seems good.
+ * If there's any issue with it it's that the code size to
+ * implement is a bit large because of the conversion
+ * to/from int and bignum that is required. There is no API
+ * that doesn't do the conversion so dead stripping will never
+ * leave that code out.
+ *
+ * The implementation itself seems correct, but not as clean
+ * and neat as it could be. It could probably be smaller too.
+ *
+ * The implementation has three main parts / functions
+ *  - The decoding of the array of two
+ *  - All the tag and type checking for the various API functions
+ *  - Conversion to/from bignum and int
+ *
+ * The type checking seems like it wastes the most code for
+ * what it needs to do.
+ *
+ * The inlining for the conversion is probably making the
+ * overall code base larger.
+ *
+ * The tests cases could be organized a lot better and be
+ * more thorough.
+ *
+ * Seems also like there could be more common code in the
+ * first tier part of the public API. Some functions only
+ * vary by a TagSpec.
+ */
 static void ProcessMantissaAndExponent(QCBORDecodeContext *pMe,
                                        TagSpecification    TagSpec,
                                        QCBORItem          *pItem,
@@ -5518,10 +5717,12 @@
 
       case QCBOR_TYPE_DECIMAL_FRACTION:
       case QCBOR_TYPE_BIGFLOAT:
-         *pnMantissa = pItem->val.expAndMantissa.Mantissa.nInt;
          *pnExponent = pItem->val.expAndMantissa.nExponent;
+         *pnMantissa = pItem->val.expAndMantissa.Mantissa.nInt;
          break;
 
+#ifndef QCBOR_DISABLE_TAGS
+      /* If tags are disabled, mantissas can never be big nums */
       case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
       case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
          *pnExponent = pItem->val.expAndMantissa.nExponent;
@@ -5533,6 +5734,7 @@
          *pnExponent = pItem->val.expAndMantissa.nExponent;
          uErr = ConvertNegativeBigNumToSigned(pItem->val.expAndMantissa.Mantissa.bigNum, pnMantissa);
          break;
+#endif /* QCBOR_DISABLE_TAGS */
 
       default:
          uErr = QCBOR_ERR_UNEXPECTED_TYPE;
@@ -5575,6 +5777,8 @@
          *pnExponent = pItem->val.expAndMantissa.nExponent;
          break;
 
+#ifndef QCBOR_DISABLE_TAGS
+      /* If tags are disabled, mantissas can never be big nums */
       case QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM:
       case QCBOR_TYPE_BIGFLOAT_POS_BIGNUM:
          *pnExponent = pItem->val.expAndMantissa.nExponent;
@@ -5588,6 +5792,7 @@
          *pMantissa = pItem->val.expAndMantissa.Mantissa.bigNum;
          *pbIsNegative = true;
          break;
+#endif /* QCBOR_DISABLE_TAGS */
 
       default:
          uErr = QCBOR_ERR_UNEXPECTED_TYPE;
@@ -5690,7 +5895,7 @@
 */
 void QCBORDecode_GetDecimalFractionBig(QCBORDecodeContext *pMe,
                                        uint8_t             uTagRequirement,
-                                       UsefulBuf          MantissaBuffer,
+                                       UsefulBuf           MantissaBuffer,
                                        UsefulBufC         *pMantissa,
                                        bool               *pbMantissaIsNegative,
                                        int64_t            *pnExponent)
diff --git a/test/not_well_formed_cbor.h b/test/not_well_formed_cbor.h
index 6734e93..7cbd3c3 100644
--- a/test/not_well_formed_cbor.h
+++ b/test/not_well_formed_cbor.h
@@ -50,8 +50,10 @@
     {(uint8_t[]){0x5f, 0x80, 0xff}, 3},
     // indefinite length byte string with an map chunk
     {(uint8_t[]){0x5f, 0xa0, 0xff}, 3},
+#ifndef QCBOR_DISABLE_TAGS
     // indefinite length byte string with tagged integer chunk
     {(uint8_t[]){0x5f, 0xc0, 0x00, 0xff}, 4},
+#endif /* QCBOR_DISABLE_TAGS */
     // indefinite length byte string with an simple type chunk
     {(uint8_t[]){0x5f, 0xe0, 0xff}, 3},
     // indefinite length byte string with indefinite string inside
@@ -246,11 +248,12 @@
     {(uint8_t[]){0x1f}, 1},
     // Negative integer with "argument" an indefinite length
     {(uint8_t[]){0x3f}, 1},
+#ifndef QCBOR_DISABLE_TAGS
     // CBOR tag with "argument" an indefinite length
     {(uint8_t[]){0xdf, 0x00}, 2},
     // CBOR tag with "argument" an indefinite length alternate vector
     {(uint8_t[]){0xdf}, 1},
-
+#endif /* QCBOR_DISABLE_TAGS */
 
     // Missing content bytes from a definite length string
 
diff --git a/test/qcbor_decode_tests.c b/test/qcbor_decode_tests.c
index 431836c..742a01b 100644
--- a/test/qcbor_decode_tests.c
+++ b/test/qcbor_decode_tests.c
@@ -1758,6 +1758,10 @@
       const struct someBinaryBytes *pBytes = &paNotWellFormedCBOR[nIterate];
       const UsefulBufC Input = (UsefulBufC){pBytes->p, pBytes->n};
 
+      if(nIterate == 86) {
+         nIterate = 86;
+      }
+
       // Set up decoder context. String allocator needed for indefinite
       // string test cases
       QCBORDecodeContext DCtx;
@@ -1814,6 +1818,11 @@
       }
 #endif /* QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS */
 
+      const size_t nIndexx = (size_t)(pF - pFailInputs);
+      if(nIndexx == 8) {
+         uCBORError = 9;
+      }
+
 
       // Iterate until there is an error of some sort error
       QCBORItem Item;
@@ -1867,8 +1876,13 @@
    { {(uint8_t[]){0x5f, 0x80, 0xff}, 3}, QCBOR_ERR_INDEFINITE_STRING_CHUNK },
    // indefinite length byte string with an map chunk
    { {(uint8_t[]){0x5f, 0xa0, 0xff}, 3}, QCBOR_ERR_INDEFINITE_STRING_CHUNK },
+#ifndef QCBOR_DISABLE_TAGS
    // indefinite length byte string with tagged integer chunk
    { {(uint8_t[]){0x5f, 0xc0, 0x00, 0xff}, 4}, QCBOR_ERR_INDEFINITE_STRING_CHUNK },
+#else
+   // indefinite length byte string with tagged integer chunk
+   { {(uint8_t[]){0x5f, 0xc0, 0x00, 0xff}, 4}, QCBOR_ERR_TAGS_DISABLED },
+#endif /* QCBOR_DISABLE_TAGS */
    // indefinite length byte string with an simple type chunk
    { {(uint8_t[]){0x5f, 0xe0, 0xff}, 3}, QCBOR_ERR_INDEFINITE_STRING_CHUNK },
    { {(uint8_t[]){0x5f, 0x5f, 0x41, 0x00, 0xff, 0xff}, 6}, QCBOR_ERR_INDEFINITE_STRING_CHUNK},
@@ -1999,10 +2013,12 @@
    // double-precision with 3 byte argument
    { {(uint8_t[]){0xfb, 0x00, 0x00, 0x00}, 4}, QCBOR_ERR_HIT_END },
 
-
+#ifndef QCBOR_DISABLE_TAGS
    // Tag with no content
    { {(uint8_t[]){0xc0}, 1}, QCBOR_ERR_HIT_END },
-
+#else /* QCBOR_DISABLE_TAGS */
+   { {(uint8_t[]){0xc0}, 1}, QCBOR_ERR_TAGS_DISABLED },
+#endif /* QCBOR_DISABLE_TAGS */
 
    // Breaks must not occur in definite length arrays and maps
    // Array of length 1 with sole member replaced by a break
@@ -2094,11 +2110,16 @@
    { {(uint8_t[]){0x1f}, 1}, QCBOR_ERR_BAD_INT },
    // Negative integer with additional info indefinite length
    { {(uint8_t[]){0x3f}, 1}, QCBOR_ERR_BAD_INT },
+
+#ifndef QCBOR_DISABLE_TAGS
    // CBOR tag with "argument" an indefinite length
    { {(uint8_t[]){0xdf, 0x00}, 2}, QCBOR_ERR_BAD_INT },
    // CBOR tag with "argument" an indefinite length alternate vector
    { {(uint8_t[]){0xdf}, 1}, QCBOR_ERR_BAD_INT },
-
+#else /* QCBOR_DISABLE_TAGS */
+   { {(uint8_t[]){0xdf, 0x00}, 2}, QCBOR_ERR_TAGS_DISABLED },
+   { {(uint8_t[]){0xdf}, 1}, QCBOR_ERR_TAGS_DISABLED },
+#endif /* QCBOR_DISABLE_TAGS */
 
    // Missing bytes from a deterministic length string
    // A byte string is of length 1 without the 1 byte
@@ -2117,7 +2138,7 @@
    // Text string should have 2^64 bytes, but has 3
    { {(uint8_t[]){0x7b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                   0x01, 0x02, 0x03}, 6}, QCBOR_ERR_HIT_END },
-#else
+#else 
    // Byte string should have 2^32-15 bytes, but has one
    { {(uint8_t[]){0x5a, 0x00, 0x00, 0xff, 0xf0, 0x00}, 6}, QCBOR_ERR_HIT_END },
    // Byte string should have 2^32-15 bytes, but has one
@@ -2191,7 +2212,7 @@
    { {(uint8_t[]){0xbf, 0x00, 0x00, 0x00, 0xff}, 5}, QCBOR_ERR_BAD_BREAK },
 #endif /* QCBOR_DISABLE_INDEFINITE_LENGTH_ARRAYS */
 
-
+#ifndef QCBOR_DISABLE_TAGS
    // In addition to not-well-formed, some invalid CBOR
    // Text-based date, with an integer
    { {(uint8_t[]){0xc0, 0x00}, 2}, QCBOR_ERR_BAD_OPT_TAG },
@@ -2201,6 +2222,17 @@
    { {(uint8_t[]){0xc1, 0xc0, 0x00}, 3}, QCBOR_ERR_BAD_OPT_TAG },
    // big num tagged an int, not a byte string
    { {(uint8_t[]){0xc2, 0x00}, 2}, QCBOR_ERR_BAD_OPT_TAG },
+#else /* QCBOR_DISABLE_TAGS */
+   // Text-based date, with an integer
+   { {(uint8_t[]){0xc0, 0x00}, 2}, QCBOR_ERR_TAGS_DISABLED },
+   // Epoch date, with an byte string
+   { {(uint8_t[]){0xc1, 0x41, 0x33}, 3}, QCBOR_ERR_TAGS_DISABLED },
+   // tagged as both epoch and string dates
+   { {(uint8_t[]){0xc1, 0xc0, 0x00}, 3}, QCBOR_ERR_TAGS_DISABLED },
+   // big num tagged an int, not a byte string
+   { {(uint8_t[]){0xc2, 0x00}, 2}, QCBOR_ERR_TAGS_DISABLED },
+#endif /* QCBOR_DISABLE_TAGS */
+
 };
 
 int32_t DecodeFailureTests()
@@ -2401,7 +2433,7 @@
 #endif /* QCBOR_DISABLE_FLOAT_HW_USE */
 
 
-
+/* Test date decoding using GetNext() */
 int32_t DateParseTest()
 {
    QCBORDecodeContext DCtx;
@@ -2532,6 +2564,7 @@
    return 0;
 }
 
+
 /*
  Test cases covered here. Some items cover more than one of these.
    positive integer (zero counts as a positive integer)
@@ -2561,7 +2594,73 @@
    Untagged values
  */
 static const uint8_t spSpiffyDateTestInput[] = {
-   0x86, // array of 6 items
+   0x87, // array of 7 items
+
+   0xa6, // Open a map for tests involving untagged items with labels.
+
+   // Untagged integer 0
+   0x08,
+   0x00,
+
+   // Utagged date string with string label y
+   0x61, 0x79,
+   0x6a, '2','0','8','5','-','0','4','-','1','2', // Untagged date string
+
+   // Untagged single-precision float with value 3.14 with string label x
+   0x61, 0x78,
+   0xFA, 0x40, 0x48, 0xF5, 0xC3,
+
+   // Untagged half-precision float with value -2
+   0x09,
+   0xF9, 0xC0, 0x00,
+
+   /* Untagged date-only date string */
+   0x18, 0x63,
+   0x6A, 0x31, 0x39, 0x38, 0x35, 0x2D, 0x30, 0x34, 0x2D, 0x31, 0x32, /* "1985-04-12" */
+
+   /* Untagged days-count epoch date */
+   0x11,
+   0x19, 0x0F, 0x9A, /* 3994 */
+
+   // End of map, back to array
+
+   0xa7, // Open map of tagged items with labels
+
+   0x00,
+   0xc0, // tag for string date
+   0x6a, '1','9','8','5','-','0','4','-','1','2', // Tagged date string
+
+
+   0x01,
+   0xda, 0x03, 0x03, 0x03, 0x03, // An additional tag
+   0xc1, // tag for epoch date
+   0x1a, 0x53, 0x72, 0x4E, 0x00, // Epoch date 1400000000; Tue, 13 May 2014 16:53:20 GMT
+
+   0x05,
+   0xc1,
+   0xfb, 0xc3, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, // -9223372036854773760 largest negative
+
+
+   0x07,
+   0xc1, // tag for epoch date
+   0xfb, 0x43, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, // 9223372036854773760 largest supported
+
+   /* Tagged days-count epoch date */
+   0x63, 0x53, 0x44, 0x45,
+   0xD8, 0x64,  /* tag(100) */
+   0x39, 0x29, 0xB3, /* -10676 */
+
+   // Untagged -1000 with label z
+   0x61, 0x7a,
+   0xda, 0x01, 0x01, 0x01, 0x01, // An additional tag
+   0x39, 0x03, 0xe7,
+
+   /* Tagged date-only date string */
+   0x63, 0x53, 0x44, 0x53,
+   0xD9, 0x03, 0xEC,
+   0x6A, 0x31, 0x39, 0x38, 0x35, 0x2D, 0x30, 0x34, 0x2D, 0x31, 0x32, /* "1985-04-12" */
+
+   // End of map of tagged items
 
    0xc1,
    0xfb, 0xc3, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, // -9.2233720368547748E+18, too negative
@@ -2572,144 +2671,34 @@
    0xc1, // tag for epoch date
    0xf9, 0xfc, 0x00, // Half-precision -Infinity
 
-   0xad, // Open a map for tests involving labels.
-
-   0x00,
-   0xc0, // tag for string date
-   0x6a, '1','9','8','5','-','0','4','-','1','2', // Tagged date string
-
-   0x01,
-   0xda, 0x03, 0x03, 0x03, 0x03, // An additional tag
-   0xc1, // tag for epoch date
-   0x1a, 0x53, 0x72, 0x4E, 0x00, // Epoch date 1400000000; Tue, 13 May 2014 16:53:20 GMT
-
-   // Untagged integer 0
-   0x08,
-   0x00,
-
-   // Utagged date string with string label y
-   0x61, 0x79,
-   0x6a, '2','0','8','5','-','0','4','-','1','2', // Untagged date string
-
-   // Untagged -1000 with label z
-   0x61, 0x7a,
-   0xda, 0x01, 0x01, 0x01, 0x01, // An additional tag
-   0x39, 0x03, 0xe7,
-
-   0x07,
-   0xc1, // tag for epoch date
-   0xfb, 0x43, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, // 9223372036854773760 largest supported
-
-   0x05,
-   0xc1,
-   0xfb, 0xc3, 0xdf, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, // -9223372036854773760 largest negative
-
-   // Untagged single-precision float with value 3.14 with string label x
-   0x61, 0x78,
-   0xFA, 0x40, 0x48, 0xF5, 0xC3,
-
-   // Untagged half-precision float with value -2
-   0x09,
-   0xF9, 0xC0, 0x00,
-
-   /* Tagged date-only date string */
-   0x63, 0x53, 0x44, 0x53,
-   0xD9, 0x03, 0xEC,
-   0x6A, 0x31, 0x39, 0x38, 0x35, 0x2D, 0x30, 0x34, 0x2D, 0x31, 0x32, /* "1985-04-12" */
-
-   /* Untagged date-only date string */
-   0x18, 0x63,
-   0x6A, 0x31, 0x39, 0x38, 0x35, 0x2D, 0x30, 0x34, 0x2D, 0x31, 0x32, /* "1985-04-12" */
-
-   /* Tagged days-count epoch date */
-   0x63, 0x53, 0x44, 0x45,
-   0xD8, 0x64,  /* tag(100) */
-   0x39, 0x29, 0xB3, /* -10676 */
-
-   /* Untagged days-count epoch date */
-   0x11,
-   0x19, 0x0F, 0x9A, /* 3994 */
-
-   // End of map, back to array
-
    // These two at the end because they are unrecoverable errors
    0xc1, // tag for epoch date
    0x80, // Erroneous empty array as content for date
 
    0xc0, // tag for string date
    0xa0 // Erroneous empty map as content for date
-
 };
 
 int32_t SpiffyDateDecodeTest()
 {
    QCBORDecodeContext DC;
    QCBORError         uError;
-   int64_t            nEpochDate2, nEpochDate3, nEpochDate5,
-                      nEpochDate4, nEpochDate6, nEpochDateFail,
-                      nEpochDate1400000000, nEpochDays1, nEpochDays2;
-   UsefulBufC         StringDate1, StringDate2, StringDays1, StringDays2;
-   uint64_t           uTag1, uTag2;
+   int64_t            nEpochDate3, nEpochDate5,
+                      nEpochDate4, nEpochDate6,
+                      nEpochDays2;
+   UsefulBufC         StringDate1, StringDate2, StringDays2;
 
    QCBORDecode_Init(&DC,
                     UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spSpiffyDateTestInput),
                     QCBOR_DECODE_MODE_NORMAL);
+
+   /* Items are in an array or map to test look up by label and other
+    * that might not occur in isolated items. But it does make the
+    * test a bit messy. */
    QCBORDecode_EnterArray(&DC, NULL);
 
-   // Too-negative float, -9.2233720368547748E+18
-   QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
-   uError = QCBORDecode_GetAndResetError(&DC);
-   if(uError != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_DATE_OVERFLOW)) {
-      return 1111;
-   }
-
-   // Too-large integer
-   QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
-   uError = QCBORDecode_GetAndResetError(&DC);
-   if(uError != QCBOR_ERR_DATE_OVERFLOW) {
-      return 1;
-   }
-
-   // Half-precision minus infinity
-   QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
-   uError = QCBORDecode_GetAndResetError(&DC);
-   if(uError != FLOAT_ERR_CODE_NO_HALF_PREC_NO_FLOAT_HW(QCBOR_ERR_DATE_OVERFLOW)) {
-      return 2;
-   }
-
-
-
    QCBORDecode_EnterMap(&DC, NULL);
 
-   // Get largest negative double precision epoch date allowed
-   QCBORDecode_GetEpochDateInMapN(&DC,
-                                  5,
-                                  QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG |
-                                    QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS,
-                                  &nEpochDate2);
-   uError = QCBORDecode_GetAndResetError(&DC);
-   if(uError != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)) {
-      return 102;
-   }
-   if(uError == QCBOR_SUCCESS) {
-      if(nEpochDate2 != -9223372036854773760LL) {
-         return 101;
-      }
-   }
-
-   // Get largest double precision epoch date allowed
-   QCBORDecode_GetEpochDateInMapN(&DC, 7, QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
-                                  &nEpochDate2);
-   uError = QCBORDecode_GetAndResetError(&DC);
-   if(uError != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)) {
-      return 112;
-   }
-   if(uError == QCBOR_SUCCESS) {
-      if(nEpochDate2 != 9223372036854773760ULL) {
-         return 111;
-      }
-   }
-
    // A single-precision date
    QCBORDecode_GetEpochDateInMapSZ(&DC, "x", QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
                                    &nEpochDate5);
@@ -2772,6 +2761,39 @@
 
    // The rest of these succeed even if float features are disabled
 
+
+   // Untagged integer 0
+   QCBORDecode_GetEpochDateInMapN(&DC, 8, QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
+                                  &nEpochDate3);
+   // Untagged date string
+   QCBORDecode_GetDateStringInMapSZ(&DC, "y", QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
+                                    &StringDate2);
+
+   QCBORDecode_GetDaysStringInMapN(&DC, 99, QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
+                                   &StringDays2);
+
+   QCBORDecode_GetEpochDaysInMapN(&DC, 17, QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
+                                  &nEpochDays2);
+
+   QCBORDecode_ExitMap(&DC);
+   if(QCBORDecode_GetError(&DC) != QCBOR_SUCCESS) {
+      return 3001;
+   }
+
+   // The map of tagged items
+   QCBORDecode_EnterMap(&DC, NULL);
+
+#ifndef QCBOR_DISABLE_TAGS
+   int64_t            nEpochDate2,
+                      nEpochDateFail,
+                      nEpochDate1400000000, nEpochDays1;
+   UsefulBufC         StringDays1;
+   uint64_t           uTag1, uTag2;
+
+   // Tagged date string
+   QCBORDecode_GetDateStringInMapN(&DC, 0, QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+                                   &StringDate1);
+
    // Epoch date 1400000000; Tue, 13 May 2014 16:53:20 GMT
    QCBORDecode_GetEpochDateInMapN(&DC,
                                   1,
@@ -2779,15 +2801,23 @@
                                     QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS,
                                   &nEpochDate1400000000);
    uTag1 = QCBORDecode_GetNthTagOfLast(&DC, 0);
-   // Tagged date string
-   QCBORDecode_GetDateStringInMapN(&DC, 0, QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
-                                   &StringDate1);
-   // Untagged integer 0
-   QCBORDecode_GetEpochDateInMapN(&DC, 8, QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
-                                  &nEpochDate3);
-   // Untagged date string
-   QCBORDecode_GetDateStringInMapSZ(&DC, "y", QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
-                                    &StringDate2);
+
+   // Get largest negative double precision epoch date allowed
+   QCBORDecode_GetEpochDateInMapN(&DC,
+                                  5,
+                                  QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG |
+                                    QCBOR_TAG_REQUIREMENT_ALLOW_ADDITIONAL_TAGS,
+                                  &nEpochDate2);
+   uError = QCBORDecode_GetAndResetError(&DC);
+   if(uError != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)) {
+      return 102;
+   }
+   if(uError == QCBOR_SUCCESS) {
+      if(nEpochDate2 != -9223372036854773760LL) {
+         return 101;
+      }
+   }
+
    // Untagged -1000 with label z
    QCBORDecode_GetEpochDateInMapSZ(&DC,
                                    "z",
@@ -2796,6 +2826,20 @@
                                    &nEpochDate6);
    uTag2 = QCBORDecode_GetNthTagOfLast(&DC, 0);
 
+
+   // Get largest double precision epoch date allowed
+   QCBORDecode_GetEpochDateInMapN(&DC, 7, QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+                                  &nEpochDate2);
+   uError = QCBORDecode_GetAndResetError(&DC);
+   if(uError != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)) {
+      return 112;
+   }
+   if(uError == QCBOR_SUCCESS) {
+      if(nEpochDate2 != 9223372036854773760ULL) {
+         return 111;
+      }
+   }
+
    /* The days format is much simpler than the date format
     * because it can't be a floating point value. The test
     * of the spiffy decode functions sufficiently covers
@@ -2807,20 +2851,36 @@
    QCBORDecode_GetDaysStringInMapSZ(&DC, "SDS", QCBOR_TAG_REQUIREMENT_TAG,
                                     &StringDays1);
 
-   QCBORDecode_GetDaysStringInMapN(&DC, 99, QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
-                                   &StringDays2);
-
    QCBORDecode_GetEpochDaysInMapSZ(&DC, "SDE", QCBOR_TAG_REQUIREMENT_TAG,
                                    &nEpochDays1);
 
-   QCBORDecode_GetEpochDaysInMapN(&DC, 17, QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
-                                  &nEpochDays2);
-
    QCBORDecode_ExitMap(&DC);
    if(QCBORDecode_GetError(&DC) != QCBOR_SUCCESS) {
       return 3001;
    }
 
+   // Too-negative float, -9.2233720368547748E+18
+   QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
+   uError = QCBORDecode_GetAndResetError(&DC);
+   if(uError != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_DATE_OVERFLOW)) {
+      return 1111;
+   }
+
+   // Too-large integer
+   QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
+   uError = QCBORDecode_GetAndResetError(&DC);
+   if(uError != QCBOR_ERR_DATE_OVERFLOW) {
+      return 1;
+   }
+
+   // Half-precision minus infinity
+   QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
+   uError = QCBORDecode_GetAndResetError(&DC);
+   if(uError != FLOAT_ERR_CODE_NO_HALF_PREC_NO_FLOAT_HW(QCBOR_ERR_DATE_OVERFLOW)) {
+      return 2;
+   }
+
+
    // Bad content for epoch date
    QCBORDecode_GetEpochDate(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nEpochDateFail);
    uError = QCBORDecode_GetAndResetError(&DC);
@@ -2840,6 +2900,17 @@
    if(uError != QCBOR_ERR_UNRECOVERABLE_TAG_CONTENT) {
       return 1000 + (int32_t)uError;
    }
+#else /* QCBOR_DISABLE_TAGS */
+   QCBORDecode_GetDateStringInMapN(&DC, 0, QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+                                   &StringDate1);
+   uError = QCBORDecode_GetAndResetError(&DC);
+   if(uError != QCBOR_ERR_TAGS_DISABLED) {
+      return 4;
+   }
+#endif /* QCBOR_DISABLE_TAGS */
+
+
+#ifndef QCBOR_DISABLE_TAGS
 
    if(nEpochDate1400000000 != 1400000000) {
       return 200;
@@ -2849,36 +2920,38 @@
       return 201;
    }
 
-   if(nEpochDate3 != 0) {
-      return 202;
+   if(nEpochDays1 != -10676) {
+      return 205;
    }
 
-   if(nEpochDate6 != -1000) {
-      return 203;
+   if(UsefulBuf_Compare(StringDays1, UsefulBuf_FromSZ("1985-04-12"))) {
+      return 207;
    }
 
    if(uTag2 != 0x01010101) {
       return 204;
    }
 
-   if(nEpochDays1 != -10676) {
-      return 205;
-   }
-
-   if(nEpochDays2 != 3994) {
-      return 206;
+   if(nEpochDate6 != -1000) {
+      return 203;
    }
 
    if(UsefulBuf_Compare(StringDate1, UsefulBuf_FromSZ("1985-04-12"))) {
       return 205;
    }
 
-   if(UsefulBuf_Compare(StringDate2, UsefulBuf_FromSZ("2085-04-12"))) {
+#endif /* QCBOR_DISABLE_TAGS */
+
+   if(nEpochDate3 != 0) {
+      return 202;
+   }
+
+   if(nEpochDays2 != 3994) {
       return 206;
    }
 
-   if(UsefulBuf_Compare(StringDays1, UsefulBuf_FromSZ("1985-04-12"))) {
-      return 207;
+   if(UsefulBuf_Compare(StringDate2, UsefulBuf_FromSZ("2085-04-12"))) {
+      return 206;
    }
 
    if(UsefulBuf_Compare(StringDays2, UsefulBuf_FromSZ("1985-04-12"))) {
@@ -2889,7 +2962,6 @@
 }
 
 
-
 // Input for one of the tagging tests
 static const uint8_t spTagInput[] = {
    0xd9, 0xd9, 0xf7, // CBOR magic number
@@ -3530,8 +3602,19 @@
    return 0;
 }
 
-
-
+/*
+ * These are showing the big numbers converted to integers.
+ * The tag numbers are not shown.
+ *
+ * [ 18446744073709551616,
+ *   -18446744073709551617,
+ *   {"BN+": 18446744073709551616,
+ *     64: 18446744073709551616,
+ *     "BN-": -18446744073709551617,
+ *     -64: -18446744073709551617
+ *   }
+ * ]
+ */
 
 static const uint8_t spBigNumInput[] = {
  0x83,
@@ -3547,10 +3630,12 @@
     0x38, 0x3F,
        0xC3, 0x49, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
 
+#ifndef QCBOR_DISABLE_TAGS
 /* The expected big num */
 static const uint8_t spBigNum[] = {
    0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00};
+#endif /* QCBOR_DISABLE_TAGS */
 
 
 int32_t BignumParseTest()
@@ -3571,6 +3656,7 @@
       return -2;
    }
 
+#ifndef QCBOR_DISABLE_TAGS
    //
    if((nCBORError = QCBORDecode_GetNext(&DCtx, &Item)))
       return -3;
@@ -3627,6 +3713,12 @@
       UsefulBuf_Compare(Item.val.bigNum, UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spBigNum))){
       return -16;
    }
+#else
+
+   if(QCBORDecode_GetNext(&DCtx, &Item) != QCBOR_ERR_TAGS_DISABLED) {
+      return -100;
+   }
+#endif /* QCBOR_DISABLE_TAGS */
 
    return 0;
 }
@@ -4015,6 +4107,8 @@
    QCBORDecode_Init(&DC, IndefLen, QCBOR_DECODE_MODE_NORMAL);
 
    nResult = QCBORDecode_GetNext(&DC, &Item);
+
+#ifndef QCBOR_DISABLE_TAGS
    if(nResult || Item.uDataType != QCBOR_TYPE_ARRAY) {
       return -18;
    }
@@ -4023,6 +4117,11 @@
    if(nResult != QCBOR_ERR_BAD_BREAK) {
       return -19;
    }
+#else /* QCBOR_DISABLE_TAGS */
+   if(nResult != QCBOR_ERR_TAGS_DISABLED) {
+      return -20;
+   }
+#endif /* QCBOR_DISABLE_TAGS */
 
     return 0;
 }
@@ -4549,41 +4648,525 @@
 
 #ifndef QCBOR_DISABLE_EXP_AND_MANTISSA
 
-/*  exponent, mantissa
-  [
-    4([-1, 3]),
-    4([-20,                   4759477275222530853136]),
-    4([9223372036854775807,  -4759477275222530853137]),
-    5([300, 100]),
-    5([-20,                   4759477275222530853136]),
-    5([-9223372036854775807, -4759477275222530853137])
-    5([ 9223372036854775806, -4759477275222530853137])
-    5([ 9223372036854775806,  9223372036854775806])]
-  ]
- */
-static const uint8_t spExpectedExponentsAndMantissas[] = {
-   0x88,
-   0xC4, 0x82, 0x20,
-               0x03,
-   0xC4, 0x82, 0x33,
-               0xC2, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,
-   0xC4, 0x82, 0x1B, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
-               0xC3, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,
-   0xC5, 0x82, 0x19, 0x01, 0x2C,
-               0x18, 0x64,
-   0xC5, 0x82, 0x33,
-               0xC2, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,
-   0xC5, 0x82, 0x3B, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE,
-               0xC3, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,
-   0xC5, 0x82, 0x1B, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE,
-               0xC3, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,
-   0xC5, 0x82, 0x1B, 0x7f, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE,
-               0x1B, 0x7f, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFE
+struct EaMTest {
+   const char *szName;
+   UsefulBufC  Input;
+   uint8_t     uTagRequirement;
+   bool        bHasTags;
+
+   /* Expected values for GetNext */
+   QCBORError  uExpectedErrorGN;
+   uint8_t     uQCBORTypeGN;
+   int64_t     nExponentGN;
+   int64_t     nMantissaGN;
+   UsefulBufC  MantissaGN;
+
+   /* Expected values for GetDecimalFraction */
+   QCBORError  uExpectedErrorGDF;
+   int64_t     nExponentGDF;
+   int64_t     nMantissaGDF;
+
+   /* Expected values for GetDecimalFractionBig */
+   QCBORError  uExpectedErrorGDFB;
+   int64_t     nExponentGDFB;
+   UsefulBufC  MantissaGDFB;
+   bool        IsNegativeGDFB;
+
+   /* Expected values for GetBigFloat */
+   QCBORError  uExpectedErrorGBF;
+   int64_t     nExponentGBF;
+   int64_t     nMantissaGBF;
+
+   /* Expected values for GetBigFloatBig */
+   QCBORError  uExpectedErrorGBFB;
+   int64_t     nExponentGBFB;
+   UsefulBufC  MantissaGBFB;
+   bool        IsNegativeGBFB;
 };
 
 
-int32_t ExponentAndMantissaDecodeTests(void)
+
+static const struct EaMTest pEaMTests[] = {
+   {
+      "1. Untagged pair (big float or decimal fraction), no tag required",
+      {(const uint8_t []){0x82, 0x20, 0x03}, 3},
+      QCBOR_TAG_REQUIREMENT_NOT_A_TAG,
+      false,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_ARRAY,
+      0,
+      0,
+      {(const uint8_t []){0x00}, 1},
+
+      QCBOR_SUCCESS, /* GetDecimalFraction */
+      -1,
+      3,
+
+      QCBOR_SUCCESS, /* for GetDecimalFractionBig */
+      -1,
+      {(const uint8_t []){0x03}, 1},
+      false,
+
+      QCBOR_SUCCESS, /* for GetBigFloat */
+      -1,
+      3,
+
+      QCBOR_SUCCESS, /* for GetBigFloatBig */
+      -1,
+      {(const uint8_t []){0x03}, 1},
+      false
+   },
+
+   {
+      "2. Untagged pair (big float or decimal fraction), tag required",
+      {(const uint8_t []){0x82, 0x20, 0x03}, 3},
+      QCBOR_TAG_REQUIREMENT_TAG,
+      false,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_ARRAY,
+      0,
+      0,
+      {(const uint8_t []){0x00}, 1},
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetDecimalFractionBig */
+      0,
+      {(const uint8_t []){0x00}, 1},
+      false,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloat */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloatBig */
+      0,
+      {(const uint8_t []){0x00}, 1},
+      false
+
+   },
+
+   {
+      "3. Tagged 1.5 decimal fraction, tag 4 optional",
+      {(const uint8_t []){0xC4, 0x82, 0x20, 0x03}, 4},
+      QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+      true,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_DECIMAL_FRACTION,
+      -1,
+      3,
+      {(const uint8_t []){0x00}, 1},
+
+
+      QCBOR_SUCCESS, /* for GetDecimalFraction */
+      -1,
+      3,
+
+      QCBOR_SUCCESS, /* for GetDecimalFractionBig */
+      -1,
+      {(const uint8_t []){0x03}, 1},
+      false,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloat */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloatBig */
+      0,
+      {(const uint8_t []){0x00}, 1},
+      false
+   },
+   {
+      "4. Tagged 100 * 2^300 big float, tag 5 optional",
+      {(const uint8_t []){0xC5, 0x82, 0x19, 0x01, 0x2C, 0x18, 0x64}, 7},
+      QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+      true,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_BIGFLOAT,
+      300,
+      100,
+      {(const uint8_t []){0x00}, 1},
+
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetDecimalFractionBig */
+      0,
+      {(const uint8_t []){0x03}, 1},
+      false,
+
+      QCBOR_SUCCESS, /* for GetBigFloat */
+      300,
+      100,
+
+      QCBOR_SUCCESS, /* for GetBigFloatBig */
+      300,
+      {(const uint8_t []){0x64}, 1},
+      false
+   },
+
+   {
+      "5. Tagged 4([-20, 4759477275222530853136]) decimal fraction, tag 4 required",
+      {(const uint8_t []){0xC4, 0x82, 0x33,
+                          0xC2, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10,}, 15},
+      QCBOR_TAG_REQUIREMENT_TAG,
+      true,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
+      -20,
+      0,
+      {(const uint8_t []){0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 10},
+
+      QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW, /* for GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_SUCCESS, /* for GetDecimalFractionBig */
+      -20,
+      {(const uint8_t []){0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 10},
+      false,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloat */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloatBig */
+      0,
+      {(const uint8_t []){0x00}, 0},
+      false
+   },
+
+   {
+      "6. Error: Mantissa and exponent inside a Mantissa and exponent",
+      {(const uint8_t []){0xC4, 0x82, 0x33,
+                          0xC5, 0x82, 0x19, 0x01, 0x2C, 0x18, 0x64}, 10},
+      QCBOR_TAG_REQUIREMENT_TAG,
+      true,
+
+      QCBOR_ERR_BAD_EXP_AND_MANTISSA, /* for GetNext */
+      QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM,
+      0,
+      0,
+      {(const uint8_t []){0x00}, 0},
+
+      QCBOR_ERR_BAD_EXP_AND_MANTISSA, /* for GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_ERR_BAD_EXP_AND_MANTISSA, /* for GetDecimalFractionBig */
+      0,
+      {(const uint8_t []){0x00}, 0},
+      false,
+
+      QCBOR_ERR_BAD_EXP_AND_MANTISSA, /* for GetBigFloat */
+      0,
+      0,
+
+      QCBOR_ERR_BAD_EXP_AND_MANTISSA, /* for GetBigFloatBig */
+      0,
+      {(const uint8_t []){0x00}, 0},
+      false
+   },
+   {
+      "7. Tagged 5([-20, 4294967295]) big float, big num mantissa, tag 5 required",
+      {(const uint8_t []){0xC5, 0x82, 0x33,
+                          0xC2, 0x44, 0xff, 0xff, 0xff, 0xff}, 9},
+      QCBOR_TAG_REQUIREMENT_TAG,
+      true,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_BIGFLOAT_POS_BIGNUM,
+      -20,
+      0,
+      {(const uint8_t []){0xff, 0xff, 0xff, 0xff}, 4},
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetDecimalFractionBig */
+      -20,
+      {(const uint8_t []){0x00}, 1},
+      false,
+
+      QCBOR_SUCCESS, /* for GetBigFloat */
+      -20,
+      4294967295,
+
+      QCBOR_SUCCESS, /* for GetBigFloatBig */
+      -20,
+      {(const uint8_t []){0xff, 0xff, 0xff, 0xff}, 4},
+      false
+   },
+
+   {
+      /* Special case for test 8. Don't renumber it. */
+      "8. Untagged pair with big num (big float or decimal fraction), tag optional",
+      {(const uint8_t []){0x82, 0x33, 0xC2, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 14},
+      QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+      true,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_ARRAY,
+      0,
+      0,
+      {(const uint8_t []){0x00}, 1},
+
+      QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW, /* GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_SUCCESS, /* for GetDecimalFractionBig */
+      -20,
+      {(const uint8_t []){0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 10},
+      false,
+
+      QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW, /* for GetBigFloat */
+      0,
+      0,
+
+      QCBOR_SUCCESS, /* for GetBigFloatBig */
+      -20,
+      {(const uint8_t []){0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 10},
+      false
+   },
+
+   {
+      "9. decimal fraction with large exponent and negative big num mantissa",
+      {(const uint8_t []){0xC4, 0x82, 0x1B, 0x7F, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+                                0xC3, 0x4A, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 23},
+      QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
+      true,
+
+      QCBOR_SUCCESS, /* for GetNext */
+      QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM,
+      9223372036854775807,
+      0,
+      {(const uint8_t []){0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 10},
+
+      QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW, /* GetDecimalFraction */
+      0,
+      0,
+
+      QCBOR_SUCCESS, /* for GetDecimalFractionBig */
+      9223372036854775807,
+      {(const uint8_t []){0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x10}, 10},
+      true,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloat */
+      0,
+      0,
+
+      QCBOR_ERR_UNEXPECTED_TYPE, /* for GetBigFloatBig */
+      0,
+      {(const uint8_t []){0x00}, 1},
+      false
+   },
+};
+
+
+
+int32_t ProcessEaMTests(void)
 {
+   size_t                 uIndex;
+   QCBORDecodeContext     DCtx;
+   QCBORItem              Item;
+   QCBORError             uError;
+   int64_t                nMantissa, nExponent;
+   MakeUsefulBufOnStack(  MantissaBuf, 200);
+   UsefulBufC             Mantissa;
+   bool                   bMantissaIsNegative;
+
+   for(uIndex = 0; uIndex < C_ARRAY_COUNT(pEaMTests, struct EaMTest); uIndex++) {
+      const struct EaMTest *pT = &pEaMTests[uIndex];
+      /* Decode with GetNext */
+      QCBORDecode_Init(&DCtx, pT->Input, 0);
+
+      if(uIndex + 1 == 9) {
+         nExponent = 99; // just to set a break point
+      }
+
+      uError = QCBORDecode_GetNext(&DCtx, &Item);
+#ifdef QCBOR_DISABLE_TAGS
+      /* Test 8 is a special case when tags are disabled */
+      if(pT->bHasTags && uIndex + 1 != 8) {
+         if(uError != QCBOR_ERR_TAGS_DISABLED) {
+            return (int32_t)(1+uIndex) * 1000 + 9;
+         }
+      } else {
+#endif
+         /* Now check return code, data type, mantissa and exponent */
+         if(pT->uExpectedErrorGN != uError) {
+            return (int32_t)(1+uIndex) * 1000 + 1;
+         }
+         if(uError == QCBOR_SUCCESS && pT->uQCBORTypeGN != QCBOR_TYPE_ARRAY) {
+            if(pT->uQCBORTypeGN != Item.uDataType) {
+               return (int32_t)(1+uIndex) * 1000 + 2;
+            }
+            if(pT->nExponentGN != Item.val.expAndMantissa.nExponent) {
+               return (int32_t)(1+uIndex) * 1000 + 3;
+            }
+            if(Item.uDataType == QCBOR_TYPE_DECIMAL_FRACTION || Item.uDataType == QCBOR_TYPE_BIGFLOAT ) {
+               if(pT->nMantissaGN != Item.val.expAndMantissa.Mantissa.nInt) {
+                   return (int32_t)(1+uIndex) * 1000 + 4;
+                }
+            } else {
+               if(UsefulBuf_Compare(Item.val.expAndMantissa.Mantissa.bigNum, pT->MantissaGN)) {
+                   return (int32_t)(1+uIndex) * 1000 + 5;
+               }
+            }
+         }
+#ifdef QCBOR_DISABLE_TAGS
+      }
+#endif
+
+      /* Decode with GetDecimalFraction */
+      QCBORDecode_Init(&DCtx, pT->Input, 0);
+      QCBORDecode_GetDecimalFraction(&DCtx,
+                                      pT->uTagRequirement,
+                                     &nMantissa,
+                                     &nExponent);
+      uError = QCBORDecode_GetAndResetError(&DCtx);
+#ifdef QCBOR_DISABLE_TAGS
+      if(pT->bHasTags) {
+         if(uError != QCBOR_ERR_TAGS_DISABLED) {
+            return (int32_t)(1+uIndex) * 1000 + 39;
+         }
+      } else {
+#endif
+         /* Now check return code, mantissa and exponent */
+         if(pT->uExpectedErrorGDF != uError) {
+            return (int32_t)(1+uIndex) * 1000 + 31;
+         }
+         if(uError == QCBOR_SUCCESS) {
+            if(pT->nExponentGDF != nExponent) {
+               return (int32_t)(1+uIndex) * 1000 + 32;
+            }
+            if(pT->nMantissaGDF != nMantissa) {
+                return (int32_t)(1+uIndex) * 1000 + 33;
+            }
+         }
+#ifdef QCBOR_DISABLE_TAGS
+      }
+#endif
+
+      /* Decode with GetDecimalFractionBig */
+      QCBORDecode_Init(&DCtx, pT->Input, 0);
+      QCBORDecode_GetDecimalFractionBig(&DCtx,
+                                 pT->uTagRequirement,
+                                 MantissaBuf,
+                                 &Mantissa,
+                                 &bMantissaIsNegative,
+                                 &nExponent);
+      uError = QCBORDecode_GetAndResetError(&DCtx);
+#ifdef QCBOR_DISABLE_TAGS
+      if(pT->bHasTags) {
+         if(uError != QCBOR_ERR_TAGS_DISABLED) {
+            return (int32_t)(1+uIndex) * 1000 + 49;
+         }
+      } else {
+#endif
+         /* Now check return code, mantissa (bytes and sign) and exponent */
+         if(pT->uExpectedErrorGDFB != uError) {
+            return (int32_t)(1+uIndex) * 1000 + 41;
+         }
+         if(uError == QCBOR_SUCCESS) {
+            if(pT->nExponentGDFB != nExponent) {
+               return (int32_t)(1+uIndex) * 1000 + 42;
+            }
+            if(pT->IsNegativeGDFB != bMantissaIsNegative) {
+                return (int32_t)(1+uIndex) * 1000 + 43;
+            }
+            if(UsefulBuf_Compare(Mantissa, pT->MantissaGDFB)) {
+                return (int32_t)(1+uIndex) * 1000 + 44;
+            }
+         }
+#ifdef QCBOR_DISABLE_TAGS
+      }
+#endif
+
+      /* Decode with GetBigFloat */
+      QCBORDecode_Init(&DCtx, pT->Input, 0);
+      QCBORDecode_GetBigFloat(&DCtx,
+                              pT->uTagRequirement,
+                              &nMantissa,
+                              &nExponent);
+      uError = QCBORDecode_GetAndResetError(&DCtx);
+#ifdef QCBOR_DISABLE_TAGS
+      if(pT->bHasTags) {
+         if(uError != QCBOR_ERR_TAGS_DISABLED) {
+            return (int32_t)(1+uIndex) * 1000 + 19;
+         }
+      } else {
+#endif
+         /* Now check return code, mantissa and exponent */
+         if(pT->uExpectedErrorGBF != uError) {
+            return (int32_t)(1+uIndex) * 1000 + 11;
+         }
+         if(uError == QCBOR_SUCCESS) {
+            if(pT->nExponentGBF != nExponent) {
+               return (int32_t)(1+uIndex) * 1000 + 12;
+            }
+            if(pT->nMantissaGBF != nMantissa) {
+                return (int32_t)(1+uIndex) * 1000 + 13;
+            }
+         }
+#ifdef QCBOR_DISABLE_TAGS
+      }
+#endif
+
+      /* Decode with GetBigFloatBig */
+      QCBORDecode_Init(&DCtx, pT->Input, 0);
+      QCBORDecode_GetBigFloatBig(&DCtx,
+                                 pT->uTagRequirement,
+                                 MantissaBuf,
+                                 &Mantissa,
+                                 &bMantissaIsNegative,
+                                 &nExponent);
+      uError = QCBORDecode_GetAndResetError(&DCtx);
+#ifdef QCBOR_DISABLE_TAGS
+      if(pT->bHasTags) {
+         if(uError != QCBOR_ERR_TAGS_DISABLED) {
+            return (int32_t)(1+uIndex) * 1000 + 29;
+         }
+      } else {
+#endif
+         /* Now check return code, mantissa (bytes and sign) and exponent */
+         if(pT->uExpectedErrorGBFB != uError) {
+            return (int32_t)(1+uIndex) * 1000 + 21;
+         }
+         if(uError == QCBOR_SUCCESS) {
+            if(pT->nExponentGBFB != nExponent) {
+               return (int32_t)(1+uIndex) * 1000 + 22;
+            }
+            if(pT->IsNegativeGBFB != bMantissaIsNegative) {
+                return (int32_t)(1+uIndex) * 1000 + 23;
+            }
+            if(UsefulBuf_Compare(Mantissa, pT->MantissaGBFB)) {
+                return (int32_t)(1+uIndex) * 1000 + 24;
+            }
+         }
+#ifdef QCBOR_DISABLE_TAGS
+      }
+#endif
+   }
+
+   return 0;
+}
+
+
+int32_t ExponentAndMantissaDecodeTestsSecondary(void)
+{
+#ifndef QCBOR_DISABLE_TAGS
    QCBORDecodeContext DC;
    QCBORError         uErr;
    QCBORItem          item;
@@ -4593,111 +5176,6 @@
    UsefulBufC BN = UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spBigNumMantissa);
 
 
-   QCBORDecode_Init(&DC,
-                    UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spExpectedExponentsAndMantissas),
-                    QCBOR_DECODE_MODE_NORMAL);
-
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 1;
-   }
-
-   if(item.uDataType != QCBOR_TYPE_ARRAY) {
-      return 2;
-   }
-
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 3;
-   }
-
-   if(item.uDataType != QCBOR_TYPE_DECIMAL_FRACTION ||
-      item.val.expAndMantissa.Mantissa.nInt != 3 ||
-      item.val.expAndMantissa.nExponent != -1) {
-      return 4;
-   }
-
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 5;
-   }
-
-   if(item.uDataType != QCBOR_TYPE_DECIMAL_FRACTION_POS_BIGNUM ||
-      item.val.expAndMantissa.nExponent != -20 ||
-      UsefulBuf_Compare(item.val.expAndMantissa.Mantissa.bigNum, BN)) {
-      return 6;
-   }
-
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 7;
-   }
-
-   if(item.uDataType != QCBOR_TYPE_DECIMAL_FRACTION_NEG_BIGNUM ||
-      item.val.expAndMantissa.nExponent != 9223372036854775807 ||
-      UsefulBuf_Compare(item.val.expAndMantissa.Mantissa.bigNum, BN)) {
-      return 8;
-   }
-
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 9;
-   }
-
-   if(item.uDataType != QCBOR_TYPE_BIGFLOAT ||
-      item.val.expAndMantissa.Mantissa.nInt != 100 ||
-      item.val.expAndMantissa.nExponent != 300) {
-      return 10;
-   }
-
-   // 5([-20, 4759477275222530853136]),
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 11;
-   }
-   if(item.uDataType != QCBOR_TYPE_BIGFLOAT_POS_BIGNUM ||
-      item.val.expAndMantissa.nExponent != -20 ||
-      UsefulBuf_Compare(item.val.expAndMantissa.Mantissa.bigNum, BN)) {
-      return 12;
-   }
-
-   // 5([-9223372036854775807, -4759477275222530853137])
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 13;
-   }
-   if(item.uDataType != QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM ||
-      item.val.expAndMantissa.nExponent != -9223372036854775807 ||
-      UsefulBuf_Compare(item.val.expAndMantissa.Mantissa.bigNum, BN)) {
-      return 14;
-   }
-
-   // 5([ 9223372036854775806, -4759477275222530853137])
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 15;
-   }
-   if(item.uDataType != QCBOR_TYPE_BIGFLOAT_NEG_BIGNUM ||
-      item.val.expAndMantissa.nExponent != 9223372036854775806 ||
-      UsefulBuf_Compare(item.val.expAndMantissa.Mantissa.bigNum, BN)) {
-      return 16;
-   }
-
-   // 5([ 9223372036854775806,  9223372036854775806])]
-   uErr = QCBORDecode_GetNext(&DC, &item);
-   if(uErr != QCBOR_SUCCESS) {
-      return 17;
-   }
-   if(item.uDataType != QCBOR_TYPE_BIGFLOAT ||
-      item.val.expAndMantissa.nExponent != 9223372036854775806 ||
-      item.val.expAndMantissa.Mantissa.nInt!= 9223372036854775806 ) {
-      return 18;
-   }
-
-   uErr = QCBORDecode_Finish(&DC);
-   if(uErr != QCBOR_SUCCESS) {
-      return 18;
-   }
 
    /* Now encode some stuff and then decode it */
    uint8_t pBuf[40];
@@ -4752,58 +5230,23 @@
       return 106;
    }
 
-
-   int64_t                   nExp, nMant;
-   UsefulBuf_MAKE_STACK_UB(  MantBuf, 20);
-   UsefulBufC                Mant;
-   bool                      bIsNeg;
-
-   QCBORDecode_Init(&DC,
-                    UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spExpectedExponentsAndMantissas),
-                    QCBOR_DECODE_MODE_NORMAL);
-   QCBORDecode_EnterArray(&DC, NULL);
-
-   // 4([-1, 3]),
-   QCBORDecode_GetDecimalFraction(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nExp, &nMant);
-
-   // 4([-20,                   4759477275222530853136]),
-   QCBORDecode_GetDecimalFractionBig(&DC, QCBOR_TAG_REQUIREMENT_TAG, MantBuf,
-                                     &Mant, &bIsNeg, &nExp);
-
-   // 4([9223372036854775807,  -4759477275222530853137]),
-   QCBORDecode_GetDecimalFractionBig(&DC, QCBOR_TAG_REQUIREMENT_OPTIONAL_TAG,
-                                     MantBuf, &Mant, &bIsNeg, &nExp);
-
-   // 5([300, 100]),
-   QCBORDecode_GetBigFloat(&DC, QCBOR_TAG_REQUIREMENT_TAG, &nExp, &nMant);
-
-   // 5([-20,                   4759477275222530853136]),
-   QCBORDecode_GetBigFloatBig(&DC, QCBOR_TAG_REQUIREMENT_TAG, MantBuf, &Mant,
-                              &bIsNeg, &nExp);
-
-   // 5([-9223372036854775807, -4759477275222530853137])
-   QCBORDecode_GetBigFloatBig(&DC, QCBOR_TAG_REQUIREMENT_TAG, MantBuf, &Mant,
-                              &bIsNeg, &nExp);
-
-   // 5([ 9223372036854775806, -4759477275222530853137])
-   QCBORDecode_GetBigFloatBig(&DC, QCBOR_TAG_REQUIREMENT_TAG, MantBuf, &Mant,
-                              &bIsNeg, &nExp);
-
-   // 5([ 9223372036854775806,  9223372036854775806])]
-   QCBORDecode_GetBigFloatBig(&DC, QCBOR_TAG_REQUIREMENT_TAG, MantBuf, &Mant,
-                              &bIsNeg, &nExp);
-
-   QCBORDecode_ExitArray(&DC);
-
-   uErr = QCBORDecode_Finish(&DC);
-   if(uErr != QCBOR_SUCCESS) {
-      return 200;
-   }
+#endif /* QCBOR_TAGS_DISABLED */
 
    return 0;
 }
 
 
+int32_t ExponentAndMantissaDecodeTests(void)
+{
+   int32_t rv = ProcessEaMTests();
+   if(rv) {
+      return rv;
+   }
+
+   return ExponentAndMantissaDecodeTestsSecondary();
+}
+
+
 static const struct FailInput ExponentAndMantissaFailures[] = {
    // Exponent > INT64_MAX
    { {(uint8_t[]){0xC4, 0x82, 0x1B, 0x7f, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
@@ -5211,10 +5654,14 @@
     }
  */
 static const uint8_t spRecoverableMapErrors[] = {
+#ifndef QCBOR_DISABLE_TAGS
    0xa6,
-   0x01, 0xd8, 0xe0, 0xd8, 0xe1, 0xd8, 0xe2, 0xd8, 0xe3, 0xd8, 0x04, 0x00,
-   0x03, 0x3b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0x04, 0xc1, 0xfb, 0x7e, 0x37, 0xe4, 0x3c, 0x88, 0x00, 0x75, 0x9c,
+   0x01, 0xd8, 0xe0, 0xd8, 0xe1, 0xd8, 0xe2, 0xd8, 0xe3, 0xd8, 0x04, 0x00,
+#else
+   0xa4,
+#endif
+   0x03, 0x3b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0x05, 0x00,
    0x05, 0x00,
    0x08, 0x08,
@@ -5487,6 +5934,7 @@
    int64_t nInt;
    QCBORDecode_Init(&DCtx, UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spRecoverableMapErrors), 0);
    QCBORDecode_EnterMap(&DCtx, NULL);
+#ifndef QCBOR_DISABLE_TAGS
    QCBORDecode_GetInt64InMapN(&DCtx, 0x01, &nInt);
    uErr = QCBORDecode_GetError(&DCtx);
    if(uErr != QCBOR_ERR_TOO_MANY_TAGS) {
@@ -5496,6 +5944,7 @@
       return 2121;
    }
    (void)QCBORDecode_GetAndResetError(&DCtx);
+#endif
 
 
    QCBORDecode_GetInt64InMapN(&DCtx, 0x03, &nInt);
@@ -5504,11 +5953,13 @@
       return 2023;
    }
 
+#ifndef QCBOR_DISABLE_TAGS
    QCBORDecode_GetEpochDateInMapN(&DCtx, 0x04, QCBOR_TAG_REQUIREMENT_TAG, &nInt);
    uErr = QCBORDecode_GetAndResetError(&DCtx);
    if(uErr != FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_DATE_OVERFLOW)) {
       return 2024;
    }
+#endif
 
    QCBORDecode_GetInt64InMapN(&DCtx, 0x05, &nInt);
    uErr = QCBORDecode_GetAndResetError(&DCtx);
@@ -5623,6 +6074,7 @@
       return 2600;
    }
 
+#ifndef QCBOR_DISABLE_TAGS
    QCBORDecode_Init(&DCtx, UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spBadConsumeInput2), 0);
    QCBORDecode_VGetNextConsume(&DCtx, &Item1);
    if(QCBORDecode_GetError(&DCtx) != QCBOR_SUCCESS) {
@@ -5634,6 +6086,8 @@
    if(QCBORDecode_GetError(&DCtx) != QCBOR_ERR_UNRECOVERABLE_TAG_CONTENT) {
       return 2800;
    }
+#endif
+
 
    QCBORDecode_Init(&DCtx, UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spBadConsumeInput4), 0);
    QCBORDecode_VGetNextConsume(&DCtx, &Item1);
@@ -5676,6 +6130,7 @@
 
 
 static const struct NumberConversion NumberConversions[] = {
+#ifndef QCBOR_DISABLE_TAGS
    {
       "too large to fit into int64_t",
       {(uint8_t[]){0xc3, 0x48, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, 10},
@@ -5794,77 +6249,6 @@
       FLOAT_ERR_CODE_NO_FLOAT_HW(EXP_AND_MANTISSA_ERROR(QCBOR_SUCCESS))
    },
    {
-      "Positive integer 18446744073709551615",
-      {(uint8_t[]){0x1b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, 9},
-      0,
-      QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW,
-      18446744073709551615ULL,
-      QCBOR_SUCCESS,
-      18446744073709551615.0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
-   },
-   {
-      "Positive bignum 0xffff",
-      {(uint8_t[]){0xC2, 0x42, 0xff, 0xff}, 4},
-      65536-1,
-      QCBOR_SUCCESS,
-      0xffff,
-      QCBOR_SUCCESS,
-      65535.0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
-   },
-   {
-      "Postive integer 0",
-      {(uint8_t[]){0x0}, 1},
-      0LL,
-      QCBOR_SUCCESS,
-      0ULL,
-      QCBOR_SUCCESS,
-      0.0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
-   },
-   {
-      "Negative integer -18446744073709551616",
-      {(uint8_t[]){0x3b, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }, 9},
-      -9223372036854775807-1, // INT64_MIN
-      QCBOR_SUCCESS,
-      0ULL,
-      QCBOR_ERR_NUMBER_SIGN_CONVERSION,
-      -9223372036854775808.0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
-   },
-   {
-      "Double Floating point value 100.3",
-      {(uint8_t[]){0xfb, 0x40, 0x59, 0x13, 0x33, 0x33, 0x33, 0x33, 0x33}, 9},
-      100L,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS),
-      100ULL,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS),
-      100.3,
-      FLOAT_ERR_CODE_NO_FLOAT(QCBOR_SUCCESS),
-   },
-   {
-      "Floating point value NaN 0xfa7fc00000",
-      {(uint8_t[]){0xfa, 0x7f, 0xc0, 0x00, 0x00}, 5},
-      0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_FLOAT_EXCEPTION),
-      0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_FLOAT_EXCEPTION),
-      NAN,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS),
-   },
-   {
-      "half-precision Floating point value -4",
-      {(uint8_t[]){0xf9, 0xc4, 0x00}, 3},
-      // Normal case with all enabled.
-      -4,
-      FLOAT_ERR_CODE_NO_HALF_PREC_NO_FLOAT_HW(QCBOR_SUCCESS),
-      0,
-      FLOAT_ERR_CODE_NO_HALF_PREC_NO_FLOAT_HW(QCBOR_ERR_NUMBER_SIGN_CONVERSION),
-      -4.0,
-      FLOAT_ERR_CODE_NO_HALF_PREC(QCBOR_SUCCESS)
-   },
-   {
       "Decimal fraction 3/10",
       {(uint8_t[]){0xC4, 0x82, 0x20, 0x03}, 4},
       0,
@@ -5875,17 +6259,6 @@
       FLOAT_ERR_CODE_NO_FLOAT_HW(EXP_AND_MANTISSA_ERROR(QCBOR_SUCCESS))
    },
    {
-      "+inifinity single precision",
-      {(uint8_t[]){0xfa, 0x7f, 0x80, 0x00, 0x00}, 5},
-      0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_FLOAT_EXCEPTION),
-      0,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW),
-      INFINITY,
-      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
-   },
-
-   {
       "extreme pos bignum",
       {(uint8_t[]){0xc2, 0x59, 0x01, 0x90,
          // 50 rows of 8 is 400 digits.
@@ -6038,6 +6411,90 @@
       -INFINITY,
       FLOAT_ERR_CODE_NO_FLOAT_HW(EXP_AND_MANTISSA_ERROR(QCBOR_SUCCESS))
    },
+   {
+      "Positive bignum 0xffff",
+      {(uint8_t[]){0xC2, 0x42, 0xff, 0xff}, 4},
+      65536-1,
+      QCBOR_SUCCESS,
+      0xffff,
+      QCBOR_SUCCESS,
+      65535.0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
+   },
+#endif /* QCBOR_DISABLE_TAGS */
+   {
+      "Positive integer 18446744073709551615",
+      {(uint8_t[]){0x1b, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, 9},
+      0,
+      QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW,
+      18446744073709551615ULL,
+      QCBOR_SUCCESS,
+      18446744073709551615.0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
+   },
+
+   {
+      "Postive integer 0",
+      {(uint8_t[]){0x0}, 1},
+      0LL,
+      QCBOR_SUCCESS,
+      0ULL,
+      QCBOR_SUCCESS,
+      0.0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
+   },
+   {
+      "Negative integer -18446744073709551616",
+      {(uint8_t[]){0x3b, 0x7f, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }, 9},
+      -9223372036854775807-1, // INT64_MIN
+      QCBOR_SUCCESS,
+      0ULL,
+      QCBOR_ERR_NUMBER_SIGN_CONVERSION,
+      -9223372036854775808.0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
+   },
+   {
+      "Double Floating point value 100.3",
+      {(uint8_t[]){0xfb, 0x40, 0x59, 0x13, 0x33, 0x33, 0x33, 0x33, 0x33}, 9},
+      100L,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS),
+      100ULL,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS),
+      100.3,
+      FLOAT_ERR_CODE_NO_FLOAT(QCBOR_SUCCESS),
+   },
+   {
+      "Floating point value NaN 0xfa7fc00000",
+      {(uint8_t[]){0xfa, 0x7f, 0xc0, 0x00, 0x00}, 5},
+      0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_FLOAT_EXCEPTION),
+      0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_FLOAT_EXCEPTION),
+      NAN,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS),
+   },
+   {
+      "half-precision Floating point value -4",
+      {(uint8_t[]){0xf9, 0xc4, 0x00}, 3},
+      // Normal case with all enabled.
+      -4,
+      FLOAT_ERR_CODE_NO_HALF_PREC_NO_FLOAT_HW(QCBOR_SUCCESS),
+      0,
+      FLOAT_ERR_CODE_NO_HALF_PREC_NO_FLOAT_HW(QCBOR_ERR_NUMBER_SIGN_CONVERSION),
+      -4.0,
+      FLOAT_ERR_CODE_NO_HALF_PREC(QCBOR_SUCCESS)
+   },
+   {
+      "+inifinity single precision",
+      {(uint8_t[]){0xfa, 0x7f, 0x80, 0x00, 0x00}, 5},
+      0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_FLOAT_EXCEPTION),
+      0,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_ERR_CONVERSION_UNDER_OVER_FLOW),
+      INFINITY,
+      FLOAT_ERR_CODE_NO_FLOAT_HW(QCBOR_SUCCESS)
+   },
+
 };
 
 
@@ -6155,6 +6612,23 @@
 
 #endif /* QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS */
 
+
+
+static const uint8_t spSequenceTestInput[] = {
+   /* 1. The valid date string "1985-04-12" */
+   0x6a, '1','9','8','5','-','0','4','-','1','2', // Date string
+
+   /* 2. */
+   0x00,
+
+   /* 3. A valid epoch date, 1400000000; Tue, 13 May 2014 16:53:20 GMT */
+   0x1a, 0x53, 0x72, 0x4E, 0x00,
+
+   /* 4. */
+   0x62, 'h', 'i',
+};
+
+
 int32_t CBORSequenceDecodeTests(void)
 {
    QCBORDecodeContext DCtx;
@@ -6164,46 +6638,43 @@
 
    // --- Test a sequence with extra bytes ---
 
-   // The input for the date test happens to be a sequence so it
-   // is reused. It is a sequence because it doesn't start as
-   // an array or map.
    QCBORDecode_Init(&DCtx,
-                    UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spDateTestInput),
+                    UsefulBuf_FROM_BYTE_ARRAY_LITERAL(spSequenceTestInput),
                     QCBOR_DECODE_MODE_NORMAL);
 
-   // Get the first item
+   // Get 1.
    uCBORError = QCBORDecode_GetNext(&DCtx, &Item);
    if(uCBORError != QCBOR_SUCCESS) {
       return 1;
    }
-   if(Item.uDataType != QCBOR_TYPE_DATE_STRING) {
+   if(Item.uDataType != QCBOR_TYPE_TEXT_STRING ) {
       return 2;
    }
 
    uCBORError = QCBORDecode_PartialFinish(&DCtx, &uConsumed);
    if(uCBORError != QCBOR_ERR_EXTRA_BYTES ||
+      uConsumed != 11) {
+      return 102;
+   }
+
+   // Get 2.
+   uCBORError = QCBORDecode_GetNext(&DCtx, &Item);
+   if(uCBORError != QCBOR_SUCCESS) {
+      return 66;
+   }
+
+   uCBORError = QCBORDecode_PartialFinish(&DCtx, &uConsumed);
+   if(uCBORError != QCBOR_ERR_EXTRA_BYTES ||
       uConsumed != 12) {
       return 102;
    }
 
-   // Get a second item
-   uCBORError = QCBORDecode_GetNext(&DCtx, &Item);
-   if(uCBORError != QCBOR_ERR_BAD_OPT_TAG) {
-      return 66;
-   }
-
-   uCBORError = QCBORDecode_PartialFinish(&DCtx, &uConsumed);
-   if(uCBORError != QCBOR_ERR_EXTRA_BYTES ||
-      uConsumed != 14) {
-      return 102;
-   }
-
-   // Get a third item
+   // Get 3.
    uCBORError = QCBORDecode_GetNext(&DCtx, &Item);
    if(uCBORError != QCBOR_SUCCESS) {
       return 2;
    }
-   if(Item.uDataType != QCBOR_TYPE_DATE_EPOCH) {
+   if(Item.uDataType != QCBOR_TYPE_INT64) {
       return 3;
    }
 
@@ -6220,7 +6691,6 @@
       return 4;
    }
 
-
    // --- Test an empty input ----
    uint8_t empty[1];
    UsefulBufC Empty = {empty, 0};
@@ -7034,6 +7504,12 @@
 
 #ifndef QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS
 
+/*
+ An array of three map entries
+ 1) Indefinite length string label for indefinite lenght byte string
+ 2) Indefinite length string label for an integer
+ 3) Indefinite length string label for an indefinite-length negative big num
+ */
 static const uint8_t spMapWithIndefLenStrings[] = {
    0xa3,
       0x7f, 0x61, 'l', 0x64, 'a', 'b', 'e', 'l' , 0x61, '1', 0xff,
@@ -7059,6 +7535,8 @@
    UsefulBufC ByteString;
    QCBORDecode_EnterMap(&DCtx, NULL);
    QCBORDecode_GetByteStringInMapSZ(&DCtx, "label1", &ByteString);
+
+#ifndef QCBOR_DISABLE_TAGS
    if(QCBORDecode_GetAndResetError(&DCtx)) {
       return 1;
    }
@@ -7083,6 +7561,7 @@
                                           "label2",
                                           0xff,
                                           &uDouble);
+
 #ifndef QCBOR_DISABLE_FLOAT_HW_USE
    if(QCBORDecode_GetAndResetError(&DCtx)) {
       return 5;
@@ -7097,13 +7576,23 @@
 #endif /* QCBOR_DISABLE_FLOAT_HW_USE */
 #endif /* USEFULBUF_DISABLE_ALL_FLOAT */
 
-
    QCBORDecode_ExitMap(&DCtx);
 
    if(QCBORDecode_Finish(&DCtx)) {
       return 99;
    }
 
+#else /* QCBOR_DISABLE_TAGS */
+   /* The big num in the input is a CBOR tag and you can't do
+    * map lookups in a map with a tag so this test does very little
+    * when tags are disabled. That is OK, the test coverage is still
+    * good when they are not.
+    */
+   if(QCBORDecode_GetAndResetError(&DCtx) != QCBOR_ERR_TAGS_DISABLED) {
+      return 1002;
+   }
+#endif /*QCBOR_DISABLE_TAGS */
+
    return 0;
 }
 #endif /* QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS */
@@ -7179,6 +7668,20 @@
 #endif /* QCBOR_DISABLE_INDEFINITE_LENGTH_ARRAYS */
 
 #ifndef QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS
+
+/*
+An array of one that contains
+ a byte string that is tagged 24 which means CBOR-encoded data
+ the byte string is an indefinite length string
+ the wrapped byte string is an array of three numbers
+ [42, 43, 44]
+
+[
+  24(
+    (_ h'83', h'18', h'2A182B', h'182C')
+  )
+]
+ */
 static const uint8_t pWrappedByIndefiniteLength[] = {
    0x81,
    0xd8, 0x18,
@@ -7779,6 +8282,7 @@
 
    // Rewind an indefnite length byte-string wrapped sequence
 #ifndef QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS
+   // TODO: rewrite this test to not use tags
    QCBORDecode_Init(&DCtx,
                     UsefulBuf_FROM_BYTE_ARRAY_LITERAL(pWrappedByIndefiniteLength),
                     0);
@@ -7787,11 +8291,13 @@
 
    QCBORDecode_EnterArray(&DCtx, NULL);
    QCBORDecode_EnterBstrWrapped(&DCtx, 2, NULL);
+#ifndef QCBOR_DISABLE_TAGS
    if(QCBORDecode_GetError(&DCtx) != QCBOR_ERR_INPUT_TOO_LARGE) {
-      /* this is what happens when trying to enter
-       indefinite-length byte string
-       wrapped CBOR.  Tolerate for now. Eventually it needs
-       to be fixed so this works, but that is not simple. */
+      /* TODO: This is what happens when trying to enter
+       * indefinite-length byte string wrapped CBOR.  Tolerate for
+       * now. Eventually it needs to be fixed so this works, but that
+       * is not simple.
+       */
       return 7300;
    }
 
@@ -7805,6 +8311,13 @@
    if(i != 42) {
       return 7220;
    }*/
+
+#else /* QCBOR_DISABLE_TAGS */
+   if(QCBORDecode_GetError(&DCtx) != QCBOR_ERR_TAGS_DISABLED) {
+      return 7301;
+   }
+#endif /* QCBOR_DISABLE_TAGS */
+
 #endif /* QCBOR_DISABLE_INDEFINITE_LENGTH_STRINGS */
 
 
diff --git a/test/run_tests.c b/test/run_tests.c
index f28f526..f2baaf1 100644
--- a/test/run_tests.c
+++ b/test/run_tests.c
@@ -99,8 +99,11 @@
     TEST_ENTRY(BasicEncodeTest),
     TEST_ENTRY(NestedMapTest),
     TEST_ENTRY(BignumParseTest),
+#ifndef QCBOR_DISABLE_TAGS
     TEST_ENTRY(OptTagParseTest),
     TEST_ENTRY(DateParseTest),
+    TEST_ENTRY(DecodeTaggedTypeTests),
+#endif /* QCBOR_DISABLE_TAGS */
     TEST_ENTRY(SpiffyDateDecodeTest),
     TEST_ENTRY(ShortBufferParseTest2),
     TEST_ENTRY(ShortBufferParseTest),
@@ -136,12 +139,12 @@
     TEST_ENTRY(EncodeLengthThirtyoneTest),
     TEST_ENTRY(CBORSequenceDecodeTests),
     TEST_ENTRY(IntToTests),
-    TEST_ENTRY(DecodeTaggedTypeTests),
     TEST_ENTRY(PeekAndRewindTest),
-#ifndef     QCBOR_DISABLE_EXP_AND_MANTISSA
-    TEST_ENTRY(EncodeLengthThirtyoneTest),
+#ifndef QCBOR_DISABLE_EXP_AND_MANTISSA
     TEST_ENTRY(ExponentAndMantissaDecodeTests),
+#ifndef QCBOR_DISABLE_TAGS
     TEST_ENTRY(ExponentAndMantissaDecodeFailTests),
+#endif /* QCBOR_DISABLE_TAGS */
     TEST_ENTRY(ExponentAndMantissaEncodeTests),
 #endif /* QCBOR_DISABLE_EXP_AND_MANTISSA */
     TEST_ENTRY(ParseEmptyMapInMapTest),