a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS027 [Section] 4.1.24 [Statement text] 
If requiresRegistration is set to "true" then the Producer MUST throw a fault when no registrationContext is supplied to an operation, other than getServiceDescription, which takes this field.
WSRP v2.0 Specification
Statement text