Thanks for the response!
Regarding your comment that the idea might be to align the javadocs with the specification first, would that be an activity that the Jakarta community would do? If so, will it be OK to use the existing JTA specification text when adding these missing conditions to the Javadoc? On the other hand, perhaps the TCK already verifies some of these behaviours and so the Javadoc can draw from the conditions tested in the TCK instead?
Thinking specifically about the issue I mentioned regarding threading support for XAResources I wonder if the fact the XAResource interface is provided by the java.sql module (rather than JTA) might pose some difficulty as we won't be in control of adding requirements that are appropriate to add to the XAResource interface itself. In principle the requirement might be able to be associated with the enlistResource(XAResource) method of the XAResource interface itself but might that lead to confusion where an XAResource implementer just uses the XAResource interface to produce their implementation and are not aware of the requirements that we add to the javax.transaction.Transaction enlistResource javadoc?
I take on board that answers to these questions are not available yet and will be part of the remit of the specification committee so I provide them to help with the discussions.