a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS199 [Section] 5.4.2.3 [Statement text] 
The Consumer SHOULD honor a handleEvents invocation returning requests to change mode or windowState provided they do not conflict with other such requests. Since the policy for handling conflicting requests is up to the Consumer implementation, Portlet developers SHOULD be aware that the impact on the overall layout MAY cause the Consumer to not honor a request to change windowState.
WSRP v2.0 Specification
Statement text