a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS053 [Section] 5.1.13 [Statement text] 
When the SOAP binding is in use, the Producer MUST either use one of the markupCharacterSets, UTF-8 or UTF-16 for the response message as the nature of XML requires the character set used for the markup to be the same as the response message.
WSRP v2.0 Specification
Statement text