In the meantime, I'm off to https://www.amazon.com/exec/obidos/ASIN/8590379868/lua-pilindex-20 . So, as noted on the modding page , SiS uses a modified version of Lua 5.2. Which means the best reference is, perhaps, the 3rd edition of PiL. (That said, the 4th edition of PiL is probably fine too -- ...