When you are creating an automation rule (butler) then you can add a so-called "tag".
Later one realizes that each tag stands for a command library.
@Trello, Please name things consistently and use different words each time.
Hence:
butler (used in the URL, old) =automation (new name)
rule = command
command library = a set of rules bundled together = you can also call it "rules library".
tag = (rules or command) library