Update wording in comments

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index ffc216e..67e286d 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -2871,7 +2871,7 @@
  *           MBEDTLS_X509_CRT_PARSE_C MBEDTLS_X509_CRL_PARSE_C,
  *           MBEDTLS_BIGNUM_C, MBEDTLS_MD_C
  *
- * This module is required for the PKCS7 parsing modules.
+ * This module is required for the PKCS #7 parsing modules.
  */
 #define MBEDTLS_PKCS7_C
 
diff --git a/include/mbedtls/pkcs7.h b/include/mbedtls/pkcs7.h
index 10a6322..39f9b04 100644
--- a/include/mbedtls/pkcs7.h
+++ b/include/mbedtls/pkcs7.h
@@ -32,12 +32,12 @@
  *    DER only.
  *  - The RFC specifies that multiple digest algorithms can be specified
  *    in the Signed Data type. Only one digest algorithm is supported in Mbed TLS.
- *  - The RFC specifies the Signed Data type can contain multiple X509 or PKCS6
+ *  - The RFC specifies the Signed Data type can contain multiple X.509 or PKCS #6
  *    certificates. In Mbed TLS, this list can only contain 0 or 1 certificates
- *    and they must be in X509 format.
+ *    and they must be in X.509 format.
  *  - The RFC specifies the Signed Data type can contain
- *    certificate-revocation lists (crls). This implementation has no support
- *    for crls so it is assumed to be an empty list.
+ *    certificate-revocation lists (CRLs). This implementation has no support
+ *    for CRLs so it is assumed to be an empty list.
  *  - The RFC allows for SignerInfo structure to optionally contain
  *    unauthenticatedAttributes and authenticatedAttributes. In Mbed TLS it is
  *    assumed these fields are empty.
diff --git a/library/pkcs7.c b/library/pkcs7.c
index d4059d7..cf05afd 100644
--- a/library/pkcs7.c
+++ b/library/pkcs7.c
@@ -42,7 +42,7 @@
 #endif
 
 /**
- * Initializes the pkcs7 structure.
+ * Initializes the mbedtls_pkcs7 structure.
  */
 void mbedtls_pkcs7_init(mbedtls_pkcs7 *pkcs7)
 {