We have numerous forms and documentation in various Microsoft formats and it would be nice to be able to attach them and have them visible on the web so we could use this as a full-blown documentation application without having to re-do all of the documents.
I have authored this article, in the documentation for this wiki template, on how to add/change the accepted file types.
http://www-10.lotus.com/ldd/docwikiwiki.nsf/dx/Allow_other_file_types_to_be_added_to_attachments
All MIME types are acceptable.
I created a requirement to make this configurable in the future.