When this came up a year ago at the developer's workshop, I
promised to come up with a 'diff' format for HTML so that
incremental modifications to a document, annotations being one
case, could be stored separately and merged efficiently.
Needless to say, I didn't follow through, but it seems like a
useful meme to reinsert. We could use UNIX diff format, ala
'patch', or I expect there is an SGML convention for doing this.
We could work toward a format this is less brittle (e.g.,
instead of 'insert after line 17', do 'insert after paragraph
3' or even 'insert after the paragraph with the following keywords').
Jay