Use proper doxygen markup to mark deprecations
diff --git a/include/polarssl/x509.h b/include/polarssl/x509.h
index 268121d..9dda082 100644
--- a/include/polarssl/x509.h
+++ b/include/polarssl/x509.h
@@ -227,8 +227,10 @@
/**
* \brief Give an known OID, return its descriptive string.
- * (Deprecated. Use oid_get_extended_key_usage() instead.)
- * Warning: only works for extended_key_usage OIDs!
+ *
+ * \deprecated Use oid_get_extended_key_usage() instead.
+ *
+ * \warning Only works for extended_key_usage OIDs!
*
* \param oid buffer containing the oid
*
@@ -239,7 +241,8 @@
/**
* \brief Give an OID, return a string version of its OID number.
- * (Deprecated. Use oid_get_numeric_string() instead)
+ *
+ * \deprecated Use oid_get_numeric_string() instead.
*
* \param buf Buffer to write to
* \param size Maximum size of buffer