This read-only enumeration (t1, e1, t3, e3), carried as a trap variable, indicates that a multi-role card has swapped role between T1 and E1, or between T3 and E3. An admin uses this to detect an unexpected or intentional line-type role change on a flexible card without inspecting the card's configuration directly. For example, a trap reporting cwTrapCardRole as e1 on a card an admin expected to remain T1 would flag an unintended role swap for investigation.