Items are complicated objects, with label, icon, type etc. properties.
When you do comparisons in a rule, you’ll generally be interested in the Item state., like fritzActiveCall.state
Call type Items are special though (special enough not to appear in openHAB docs, which is frustrating).
Call Item type state is a kind of list, so you’ll need to select the list entry before comparing to anything.
That’a about as much as I know about Call, but see examples -
