a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS181 [Section] 4.1.11 [Statement text] 
Since an event's name can be referred to in a wildcard fashion (see [Section 4.1.16]), Portlet developers are encouraged to organize their event's local names in a hierarchical manner and MUST use the '.' character to delimit levels within the hierarchy
WSRP v2.0 Specification
Statement text