As far as I remember it has something to do with the NAV file. I asked the same question some years ago. Im afraid I cant rememer the answer.

First thing type sv_cheats 1 in the console, then nav_edit 1 and nav_toggle_place_mode. Once navigation areas appear aim your crosshair at an area you want and type nav_use_place NAME, nav_toggle_place_painting after that every area you aim at will be marked with the specific name you've chosen. To finish marking areas type nav_toggle_place_painting again. When you're done with all names you want type nav_save, nav_analyze

P.S. nav_place_list - list of all place names

i dont think hes saying something (reach sands i mean). i think there has to be some sort of trigger or func, as just aiming doesnt seem logical...

Originally posted by -=Greenhourghost=-:

i dont think hes saying something (reach sands i mean). i think there has to be some sort of trigger or func, as just aiming doesnt seem logical...

Don't guess anything without trying. You will be aiming at the areas, no clicking/console commands/etc. So be carefully while aiming, because if you occasionally aim at the wrong area while moving your mouse, this area will also be selected for setting a new name.
And never - I say never - mention logic while talking about Valve products.

BTW you can't set your own location names, only standard: bombsite A, B, center, office etc. As Reach_Sands told you, use nav_place_list

Originally posted by Reach_Sands:

First thing type sv_cheats 1 in the console, then nav_edit 1 and nav_toggle_place_mode. Once navigation areas appear aim your crosshair at an area you want and type nav_use_place NAME, nav_toggle_place_painting after that every area you aim at will be marked with the specific name you've chosen. To finish marking areas type nav_toggle_place_painting again. When you're done with all names you want type nav_save, nav_analyze

♥♥♥♥ THANK YOU A LOT!!!! :D And thanks for all the other answers :) Thank You have a nice day!