There are 3 issues at question here: 1) Why don't we use the XMLDSig 1.1 spec instead of 1.0? 1.1 is in draft form, and a published specification shall not depend on a draft. Also, 1.1 is a breaking change to 1.0 - a 1.1 parser won't parse a 1.1 signature, and there are 1.0 elements that are no longer considered valid. When 1.1 moves out of draft, it would be a substantial change. 2) Why don't we use XML signature properties? XML signature properties is in draft form, and a published specification shall not depend on a draft. In addition, there is no need for anything but the signing time, and that's covered by XAdES already. There's also nothing preventing an implementer from using these extensions if they liked - it wouldn't break an existing parser. 3) Why not use the RELAX NG schemas? The RNG schemas are in draft form, and a published specification shall not depend on a draft. All 3 suggestion may be reconsidered for a future ODF version when the mentioned specifications have been approved.