According to the docs you can extend Contribute's capabilities in the same way
as Dreamweaver by editing dialogue box HTML and corresponding javascript.

What I want to do is add in two attributes for the LINK (A) tag -- "rel" and
"title". In Dreamweaver the config for that dialogue is "Hyperlink.htm" located
in C:\Program Files\Macromedia\Dreamweaver 8\Configuration\Objects\Common. I
can't find anything that looks similar in Contribute. There is a not-so-helpful
article on this site about extending Contribute but while it implies that this
is possible it doesn't actually say how to do it (whee).

I know I could do this using editable attributes in the template, but it needs
to be site-wide for my application.

Has anyone tried this successfully?