An object to be stored in the cache, manipulated, or invalidated can be identified by the application program using one of the following attributes:
The fully specified cache key, consisting of the URL and the various context-dependent fields, such as SAP language and SAP theme
A <prefix>*wildcard pattern that selects all objects with a matching <prefix>.
The e-tag - a unique key (GUID) assigned to an object when that object is created. You can use the GUID_CREATE ABAP function module to generate a unique GUID for your object.