Paul Groves asked whether anyone has written a DTD for markup of papyri.
For what it's worth, I have written a recommendation for marking up papyri
using an existing DTD--that of TEIxLite. The recommendations don't include
a facility for indicating a change of hand (although you could handle a
hand change by classing everything by the new scribe as an addition).
The recommendations represent a minimalist approach. You can see a draft
version at the following address:
I am still working on this draft, so any suggestions are welcome.