a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS128 [Section] 9.2 [Statement text] 
As the Portlet writes URLs into the markup it MUST encode them based on the markupType. For example, XML based markup requires that all "&" characters have to be encoded as "&".
WSRP v2.0 Specification
Statement text