UBL 2.1 includes two XAdES fragments for the convenience of users:
These schema fragments do not participate directly in UBL business object validation. They are imported in addition to the W3C XML DSig schema so that an XML instance that is using DSig that, in turn, is using XAdES inside of DSig will have those XAdES constructs validated.
The XAdES specification has matured since the release of UBL 2.1. Yet the 2.1 schemas are hardwired to the old XAdES schema fragments. I haven't heard any complaints from XAdES users, but I would think since the target namespace has not changed and the schema fragments have changed, that XAdES users of new features will encounter problems with the UBL 2.1 schemas.
We didn't anticipate this. I don't know if they are simply re-expressions of the old stuff and so there are no compatibility issues.
Kenneth found http://www.etsi.org/deliver/etsi_en/319100_319199/31913201/01.01.00_30/en_31913201v010100v.pdf for me (thanks!) indicating there are no other XAdES versions than v1.3.2 and v1.4.1.
However, looking at http://uri.etsi.org/01903/v1.3.2/ and http://uri.etsi.org/01903/v1.4.1/ I see dated versions 201506 and 201601 of the schema fragments. We have no idea how often these get updated. If I use the 201601 versions in UBL 2.2, how quickly will they be out of date? If these are simply re-expressions of the same constraints, perhaps they will never get out of date.
I have all of the materials, so the first draft of UBL 2.2 will have the 201601 versions, but I am wary of going final with this and would like the opinions of others regarding keeping or tossing the XAdES schema fragments.
I am of the opinion we eject the XAdES fragments in UBL 2.2 and document for our users how they would in the future include whatever XAdES fragment they wish into the schema import tree for their use.
Please add your yea/nay comments regarding "Keeping XAdES in the UBL 2.2 distribution" ... my vote is "nay".
. . . . . . . . . . Ken