When determining the subtype of a card that has gained and lost subtypes, a running total should be tracked. The final subtype that a card is determined to have is the net change in its subtypes.
I have a installed and advanced once. Runner is and makes a run, and Wendigo is the first piece of ice she encountered this turn. Is Wendigo Code Gate or not?
Along with the Breaking Subroutines on NEXT Silver, Ashigaru Rulings, it seems that ice characteristics are managed by running totals.