A similar case might have been already discussed, but I wasn't able to
find an answer in the P5-Guidelines and the archive:
I'm encoding the scholarly editions of a collection of medieval
charters. In the view of the historian and the medieval scribe, each
charter was a single text with legal value by it's own right.
Similiarily the editing scholar and the medieval scribe take the charter
as a part of collection, sometimes refering to an earlier inscribed text
("testes ut supra" ...).
In terms of TEI-P5: would the edition be a group of texts
(text/group/text) oder one single text with divisions (text/div)?