The parsing package caches information about objects in order to improve performance. This means that if any information that gets cached is changed, you need to tell MudOS to clear the cache. That's what this efun does. If the information returned by any of the applies below changes, you need to call parse_refresh() so that the parser knows it has changed. For example if the name of an object changes, or perhaps an adjective changes as a spell is cast to change it from blue to red - call parse_refresh() afterwards. The efun clears the cache for the object that called it.