Dear all, I've integrated the remarks done by Sergiu about verbose URIs, object properties and attachment versions. Just a comment about the .format. I agree with the fact that there are some degenerate cases like "How to open a .pdf" and some ambiguous cases as well like "How to open a .tar.gz" The idea here is to have a way for specifying a format even without having control about the Accept header (i.e., with a simple browser). For handling degenerate cases a simple test can be made on the page name. And the format should be a simple string with no dots so .tar.gz should actually be expressed as .tgz Frankly I find very useful to have a way of typing the URI of a page in a browser, stick a .pdf suffix and have Acrobat opened on the PDF rendering. Alternatively, a ?format=XYZ query string can be used instead of the .format convention. The .format thing, actually, is a "Railism" (e.g., see http://weblog.rubyonrails.org/2006/12/19/using-custom-mime-types). Of course we can decide whether Accept headers have higher priority or not. -Fabio