diff --git a/ndn-cpp/c/encoding/binary-xml-data.h b/ndn-cpp/c/encoding/binary-xml-data.h
index 1cc6efb..3e4747e 100644
--- a/ndn-cpp/c/encoding/binary-xml-data.h
+++ b/ndn-cpp/c/encoding/binary-xml-data.h
@@ -17,7 +17,7 @@
 
 /**
  * Encode the data packet as binary XML.
- * @param data Pointer to the data object the encode.
+ * @param data Pointer to the data object to encode.
  * @param signedFieldsBeginOffset Return the offset in the encoding of the beginning of the fields which are signed.
  * If you are not encoding in order to sign, you can ignore this returned value.
  * @param signedFieldsEndOffset Return the offset in the encoding of the end of the fields which are signed.
@@ -29,8 +29,8 @@
   (struct ndn_Data *data, unsigned int *signedFieldsBeginOffset, unsigned int *signedFieldsEndOffset, struct ndn_BinaryXmlEncoder *encoder);
 
 /**
- * Decode the data packet as binary XML.
- * @param data Pointer to the data object the decode.
+ * Decode the data packet as binary XML and set the fields in the data object.
+ * @param data Pointer to the data object whose fields are updated.
  * @param signedFieldsBeginOffset Return the offset in the input buffer of the beginning of the fields which are signed.
  * If you are not decoding in order to verify, you can ignore this returned value.
  * @param signedFieldsEndOffset Return the offset in the input buffer of the end of the fields which are signed.