Originally posted by Holy Crap:

That is the "mapcfg" feature. It allows you to change any cvar values you want when a specific map is loaded. For example, you can have a dedicated server with Classic as the default difficulty in every map, but you can load nmo_broadway and automatically switch to Nightmare difficulty exclusively without affecting other maps.

To use this feature, you have to manually create a .cfg file of the map that you want to have specific cvar changes for. For example, if you want to set the difficulty to Nightmare only on Broadway, you have to create a file named "nmo_broadway.cfg" and place it inside the "cfg" folder in your dedicated server installation folder. Then, edit the file and add the line: "sv_difficulty nightmare" in it, save and close.

After that, every time that nmo_broadway is loaded, it will automatically load with Nightmare difficulty enabled. You can do this with any cvar (for cheat protected cvars, you have to use Sourcemod to bypass that).

If you're not planning on using this feature, disregard the console message, it's only letting you know that there's no .cfg file present in the "cfg" folder, thus no custom cvar values will be set on that map.