What is the key for in buildings_units_allowed?

[EmperorBatman999]

Hello everybody, I'm trying to get back into modding after taking a break between Napoleon and Shogun 2. I need some help though with buildings_units_allowed. There is a key to the left with a specific number. What does this number do and do I have to make up a new number if I want to make units available from a different building? I want to make Rome's auxiliary units available from the Greek Periokoi military chain, for example.

An explanation on these would be appreciated.

[crzyrndm]

Keys are just unique id's specific to that table. So long as your number is unique, you won't have a problem.

[EmperorBatman999]

Thanks for the help.

I know it's not a big thing but have some rep.