I was recently reading the wikipedia article for Archival Resource Keys (ARKs, http://en.wikipedia.org/wiki/Archival_Resource_Key), and there was a bit of functionality that a resource is supposed to deliver that we don't in our system, nor do any other systems that I've seen that implement ARK URIs. From the article: "An ARK contains the label *ark:* after the URL's hostname, which sets the expectation that, when submitted to a web browser, the URL terminated by '?' returns a brief metadata record, and the URL terminated by '??' returns metadata that includes a commitment statement from the current service provider." Looking at the official documentation ( https://confluence.ucop.edu/display/Curation/ARK), they provided an example of http://ark.cdlib.org/ark:/13030/tf5p30086k? which is supposed to return something called an Electronic Resource Citation, but it doesn't work. Probably because, and correct me if I'm wrong, using question marks in a URL in this way doesn't really work in HTTP. So, has anyone successfully implemented this? Is it even worth it? I'm not sure I can even implement this in my own architecture. Maybe it would be better to recommend a standard set of request parameters that actually work in REST? Ethan