XOrigin value 8 and higher: When do I get it?

Bit 3 is set when the assignment is done through an assignment request. But what kind of assignment request is this?

My situation:

system role (Eset) has entitlements (account def and unsgroupb for custom target system)

system role can be requested via a service items in the IT Shop

When a employee requests this item an entry is made in PersonHasESet, but Xorigin gets the value 2 -> Indirect assignment.

I was expecting it to get the value 8. Or is a assignment request totally different than a IT Shop request?