This would be used on XSL, RNG and XML instance documents in various proprietary schemas.

Do you see an advantage in developing markup that would be consistent across multiple XML schemas?

It would mean writing just one XSL to say produce HTML output of that documentation, but as schema and stylesheets need to document different things, I wonder how it might work in practice?

Has anyone taken on a similar initiative in the past?

What do you use to document your XML, do you just use XML comments?

If so do you follow some convention inside a'la javadoc?

If you were to recommend different documentation markup per schema - one for RNG/RNC, one for XSL etc, what would you recommend?

Lech