...
Notice that for events, the first part of the path in a shorter link can be chosen somewhat arbitrarily, because it becomes the EID in the (internally) rewritten longer link that actually is seen by the engine. In the case of queries, the first part of the path in the shorter link must exactly match the RID. In both cases, the first part of the path (immediately following the domain name and port (if present)) must match this regular expression: re#/[\/\w.-]*#, i.e. it must begin with a forward slash, followed by letters, digits, or the underscore, period, or hypen characters only.
...