a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS016 [Section] 4.1.16 [Statement text] 
If the Consumer uses a Portlet which specifies usesMethodGet as "true", the Consumer MUST format its URLs in a manner that keeps user-agents from throwing away information (see section 9.2.4 for a description of the difficulties in using forms with method=get).
WSRP v2.0 Specification
Statement text