Takes 2 text lists and checks if they match. You can customize the matching rules and trigger 2 different events. When a match is true or when a match is false.
I use this when comparing a Thing's current data against inputs. Good for tracking when your user has made changes.

Update: Now extracts:
1. a list of common items (ala :intersect)
2. a list of unique items (the remainder of an :intersect -items that exists only in 1 list)

Now comes with a client side action and an untested server side action!