Forge Labels
From Halopedia, the Halo wiki
Forge Labels may be applied to most Forge Objects in Halo: Reach. Labels are used to identify objectives, such as flag spawn and return points for Capture the Flag, as well as to restrict almost any part to only appear when playing a particular game type on a given map.
Labels are set under "Game Type Label" in the "Advanced Options" menu for an object. To label an object the game type the label affects must first have been selected in place of "Basic Editing" in the Forge lobby.
Game-Specific
Objects also have a "Game-Specific" option which is false by default. If set to true, that object will only spawn during the game type its label falls under. To that end, each game type has a label that serves no other special purpose besides to be used with this option. In most cases this label is the name of the game type in question ("assault", "inv_slayer") or an abbreviation thereof ("ctf", "koth"). Additionally there are two labels, "ffa_only" and "team_only", which are for limiting an object to any games that fall under whichever category.[1][2]
