Preprocessor - 505e06b2/MW2-GSC-Documentation GitHub Wiki
The preprocessor syntax is similar to the one used for the C language, but much less powerful. In future versions of GSC, it is closer in functionality.
#include
This allows you to pull all of the functions from the wanted file into the current namespace. If there are functions in the included file that are declared in the current script, then there will be an error related to redeclaration. If you don't need all the functions in a file, it is recommended that you instead call them with the full path.
Example:
#include common_scripts\utility;
#include maps\mp\_utility;