Using LiteC Free. I have noticed that some of functions aren't painted red even when the engine can compile it. Also Command Help wont show what it does or what arguments it needs. Some of functions/values I have noticed:

vec_rotate
font (in TEXT* definition)
NULL
on_space
PH_RIGID,PH_SPHERE
ENABLE_FRICTION
GLIDE
IGNORE_WORLD
(probably all the modes in c_move...)

Thats what I have tested and seen. Is it a normal thing or really mistakes, because I don't know to use builtin functions if not coloured so... (thus not showing up in Command Help)