Most of my hacks can be used either standalone or included as part of a project. Usually, you'll see a
#define FreeSpace 0xB2B000
to allow this. I used to use Free_Space when I started hacking, but switched to FreeSpace after noticing other hackers preferred that variable. Unfortunately, I hadn't gone back and updated my old hacks to switch from Free_Space to FreeSpace, which caused me to spend an hour debugging a rom and figure out this was a problem.
So I've gone back and updated all the stuff in my folder. If you've used the following hacks and need to update them, take heed; the variable has changed.
FE8-Battle stats with animations off
FE8-Move and Con getters
FE8-Show weapon rank level achieved
NOTE: You can avoid the entire issue by adding "#define Free_Space FreeSpace" (or the other way around, if you use Free_Space instead) to your definitions.