a0d929ca_WSRP_v2_0_Specification__Statement_text
[#] CS064 [Section] 5.1.23 [Statement text] 
The Consumer SHOULD supply the returned values, along with any additional or updated publicValues, as the navigational state on the subsequent invocations for this use of the Portlet for at least the duration of the End-User's interactions with this aggregated page.
WSRP v2.0 Specification
Statement text