Help content services reject invalid print URLs

[lazyatom]

I've seen several people enter print urls for services that are either invalid or garbage (i.e. test.com/1 or 1.2.3.4). It might be nice for content services to be able to 'validate' a print URL by sending some kind of ping request so that can reject an invalid URL early in the process of accepting a registration.

(Of course, this might be rendered moot if the content service and the print server start negotiating directly about the print URLs).