Users of ehcache server have been discussing extending the basic CRUD operations of REST with some more advanced methods, such as deleting all elements in a cache with one DELETE operation.
You are most welcome to join what has become an informative forum thread here: https://sourceforge.net/forum/forum.php?thread_id=2546225&forum_id=322278
So far we have posts from myself, Jim Webber, Brett Dargan and others interested in creating or finding a REST convention for referring to all and specifying means of multi-get, multi-put and multi-delete.