As some of my past posts have mentioned, the OASIS group is currently working out how it wishes to extend support for change tracking in ODF. The change tracking feature allows you to have an office application remember what changes you have made and associate them with one or more revisions. There are many examples where governments might want such traceability, but small businesses are likely to find this functionality valuable too.
Late last year there was an ODF plugfest held in Brussels where it was decided that an Advanced Document Collaboration subcommittee should be formed to work out how to serialize tracked changes into ODF.
There are currently two proposals. One which is generic and tracks how the XML of the ODF is modified over time, and an extension to the limited change tracking that already exists in ODF 1.2.
As my previous posts have mentioned, I'm involved in making abiword able to produce and consume ODF files which contain tracked changes in the format of the generic proposal.
See my github for abiword and its change tracking test suite. Ganesh Paramasivam has been working to make Calligra and KOffice support the generic proposal too, and Jos van den Oever has done some hacking to enrich WebODF for change tracking.
As I have been going along implementing things in abiword, I've been clarifying some points on the oasis office-collab mailing list, and participating in some of the general conversation there too.
Some of the differences between the two proposals can have a large impact to the complexity of implementing change tracking in applications. Folks who are involved in office applications which use ODF might like to read up on the proposals and have their say on the future of this feature before a decision is made for you.
I think it is important for ODT to include a good, complete change tracking specification because it would offer all people the ability to collaborate on documents and businesses the change to know the exact extent of modifications made to documents by each party.