PERSISTENT Element 
You use the PERSISTENT element to make a parameter persistent for an entire ITS user session.
Use the macro of the Web Transaction API, see the example below.
In the flow file in the standalone ITS, the syntax is as follows:
Syntax
<state name="myState">
<module name="myModule" type="RFC">
<persistent name="posting_number"></persistent>
</module>
<persistent name="parameter1"></persistent>
</state>See the set-persistent macro of the Web Transaction API.