Sorry if I jump in this interesting discussion late, it is a busy period :( In general I do not think TEI (at least in the Guidelines) should recommend one or another way of creating IDs since there are pros and cons in each of the possible choices. I think this is a typical user or project specific problem, and I believe we should not interfere with user preferences if and when they do not goes against TEI semantics (as for the syntax of IDs). We can of course have an exemplification and even a discussion of possible approaches, but it must be clear that any solution is ok as far as TEI is concerned. The same for the granularity of the IDs. I think that TEI should still follow the regulatory idea of being as far as possible independent from specific tradition, theories and methodologies that shapes the pragmatics (and rethoric) of text encoding. Maybe customization like TEI simple could mandate one syntax or another, since its objective is precisely that of giving a more constrained tag set.
Anyway, it seems to me that generally the majority of the council would prefer to have at least some examples of ID usage on the guidelines. I would still refrain from calling them "recommendations" because of the variety of valid approaches that people are suggesting. But we can still offer two or three suggestions based on style and personal preference rather than actual effectiveness of a strategy, because it's too dependent on extra-textual contingencies. Agreed.
With the caveat I expressed above, agreed
We should probably look to see if any other XML projects have such recommendations too (DocBook, DITA, etc.).
yes, but again we must keep in mind that TEI has quite different rationales, principles and scope than DocBook, and a fortiori DITA. F