Scripts have global memory to use and pass variables through, statically. These offsets are the same between scripts of the same version, but will change with each patch.
Decompiled globals are all in hexadecimal, and look like this: Global_26BECF, or Global_40001.f_B44.
Arrays in memory are length-prefixed. This means the address to an array is not it's first element, but it's size.
Structs of variable size can be passed around and returned by functions.
This game uses Jenkins one-at-a-time hashing, used on many things within the game.
Model names, X360 natives (32-bit version of GTA), GXT entries, etc. Zorg's decompiler should know some of these and make a joaat function with the original string. However, sometimes it doesn't. Try to add a comment anywhere there is a hash with a missing translation.
This is increased by 1 whenever the player is using a shop. This usually means whenever you interact with the shop. (going into the clothes buy menu, going into the ammu-nation buy menu, in a hair cuttery and going to sit down in the chair, etc).
This is increased by 1 whenever the player enters a shop. (ammu-nation, clothing store, hair cuttery, etc)