RPMS specification and data format docs?

[fluke11]

I'm writing my own application to image a CD/DVD to a file. To accomplish keeping non-standard information in the image, I was considering an XML style file to document the oddities. But I have recently run across the statement in the Daemon Tools documentation that suggests that it is expected that RPMS will gain acceptance. However, I haven't run into any information on getting the RPMS format specification as either an open standard or even a sign-up for getting it under NDA. Is this an actual well defined format or a matter of researching and doing whatever it is that Alcohol 120% does? Is the Daemon Tools documentation intended to imply that the authors are attempting to promote other developers to support the format in their ripping applications? Or is the statement that other may soon support the format just stated as a hunch?

Please note, I'm not asking how RPMS emulation is accomplished. I already noticed a thread asking about this and a statement as to why that question can't be answered. I don't care how Daemon Tools does RPMS emulation once the data is provided to it. I'm just asking, as a disc image creator, how do I wrote the RPMS data for it in the first place?

Thanks

[DevX]

RMPS engine was once developed by us and licensed to Alcohol team as our partners. It is planned to add it to PRO too.
What concerns licensing it to someone else I have no information.