Folks, If you just take any XSD, and add a "top level" DFDL annotation including: repType="binary" byteOrder="bigEndian" .... And as well you must provide other top-level defaults for date formats, how nulls are represented by default and so forth. Doing this and then writing out the data should get you a quite standard binary format for XML transmission which ought to satisfy much of the needs of the binaryXML community. I found discussion of DFDL on public-xml-binary@w3c this week, and this notion crossed my mind that while binaryXML formats can't solve the DFDL problem, DFDL *CAN* solve the binaryXML problem. ...mikeb