In a recent ticket it was decided that 'faith' was a good candidate to have att.canonical added to it.
Similarly all the other members of model.persTraitLike should probably have this added. This consists of:
age faith langKnowledge nationality sex socecStatus trait
In most of these a use-case could be made for wanting to point out to, say, a taxonomy or authority file of some sort.
Possibly other things that can appear inside 'person' should be reconsidered at the same time.