Fix doc comment.
diff --git a/ndn-cpp/c/encoding/binary-xml-data.h b/ndn-cpp/c/encoding/binary-xml-data.h
index 8e8f13d..1cc6efb 100644
--- a/ndn-cpp/c/encoding/binary-xml-data.h
+++ b/ndn-cpp/c/encoding/binary-xml-data.h
@@ -31,9 +31,9 @@
/**
* Decode the data packet as binary XML.
* @param data Pointer to the data object the decode.
- * @param signedFieldsBeginOffset Return the offset in the encoding of the beginning of the fields which are signed.
+ * @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 encoding of the end of the fields which are signed.
+ * @param signedFieldsEndOffset Return the offset in the input buffer of the end of the fields which are signed.
* If you are not decoding in order to verify, you can ignore this returned value.
* @param decoder Pointer to the ndn_BinaryXmlDecoder struct which has been initialized with the buffer to decode.
* @return 0 for success, else an error code.