I think there are only 140 entries right now, so this one PR would be increasing it by 8 times over. Maybe we should convert the offset into a dict that has a `__missing__` method that looks it up, and if it can't find the offset, has a second dict (_offset_functions) that it looks up the offset, then calls a function with that rule code or whatever. Then you could define one function and set that for 840 keys.