I’m big on annotating bibliographic records with rich markup. If I want to save an excerpt for later use in an article, I want the source metadata embedded in the quote: record id, and page number(s) most particularly.
Aside from the fact that no application AFAIK supports this functionality, there are some real UI issues in supporting this functionality.
This got me thinking recently: what about using wiki-like markup? Maybe something like:
"Here is a quote with embedded metadata [doe99@23]”
Upon entering this in an application (web or otherwise), it’d be converted into proper XML.
Or, how about something more tricky, like you want to add emphasis to such a quote. Maybe…
"Here is a quote with +embedded+ metadata [doe99@23]”
A nested quote?
"Here is "a quote [smith87@14]” with embedded metadata [doe99@23]”
Alas, it seems nobody writing wiki software and standards has any need for this. I certainly would find it really useful though.