Originally Posted by HarryT
The reason I thought that only Mobi and PDF were supported is that - AFAIK - they are the only DRM formats which have date expiration. Do some libraries supply eBooks which don't expire?
Some university libraries do although we may decide to shift them off of this page for that reason. I believe both MS and eReader do have expiring license capability but I will have to recheck this now that you bring it up.