[Script] Is it safe to edit the game's metadata?

[Yknr]

in the Makefile for pokeemerald there is a set of defines at the beginning that set the games metadata:

TITLE       := POKEMON EMER
GAME_CODE   := BPEE
MAKER_CODE  := 01
REVISION    := 0
MODERN      ?= 0

I was wondering what all this meant and if it was used anywhere.
I looked some stuff up and was able to find out what GAME_CODE and MAKER_CODE do by looking at a gba technical documentation site (the site was problemkaputt.de/gbatek.htm#gbacartridgeheader should scroll you down to the spot automatically (it's a part of no$gba's debug help text if I'm reading it correctly)).

the parts I want to know what they do are the other ones. first, is it safe to change TITLE? second, what is MODERN? I don't see it in the docs. then lastly I assume that REVISION is the software version number talked about in the docs but I can't say for certain.

this question is entirely out of curiosity. there is no real reason for me to mess with these defines cause I don't need rumble or tilt interaction (unlocked by changing GAME_CODE). but it's fun to think about.

 

[Anon822]

TITLE is the "game title" in the rom header, changing it should be fine.
MODERN allows you to compile the game using a more modern compiler (make modern).
REVISION is indeed the "software version" number in the header, but in pokeruby and pokefirered it also determines which version of the rom is compiled (1.0, 1.1, etc.)

Btw changing GAME_CODE causes emerald to white screen on mGBA so you should probably not touch that.