(Written "locationid" (all lowercase) in the actor browser even though it's declared as "LocationID" in the script. Never mind that.)
Used for specifying a different name (which is displayed in the ScoreBoard and when using the TeamSay command) for parts of a zone.
Using LocationIDs is advisable where using a Zone's ZoneName property isn't possible (in open areas where zoning doesn't make sense, for instance). The downside of using a LocationID is that it takes the game up to two seconds to realize that a player has entered its radius, so the location info will lag a bit (most noticably when looking at the scoreboard).
Note: A great example of the use of this is CTF-LavaGiant, where all the ridges are named, despite each base being one large zone (actually two, upper and lower, but that is unrelated so I'm ignoring it ;-)).
- The name of this particular place.
- The size of this place specified as the radius of a sphere.