RuleSet for setting Interaction ID, when delay assigning is check?

Hi All,

SM 9.52

my customer SM is in a multi-tenant environment, and they like to have different interaction ticket prefix for each tenant, I'm trying to find out in the srvicedesk workflow which ruleset is being used to set the interaction ID, when delay assigning is check, so that i can configure the ruleset.

Can anyone advice which ruleset should i change?