Town Control

[Blackcloud6]

Many scenarios define  certain groups of town hexes as a certain town such as " The town on Board 107 is Couvains."  Then the victory conditions require one of the other sides to control the defined town usually as one of the objectives to achieve.

So what defines controlling a town?

1. Controlling all of the town hexes?
2. Controlling a majority of the hexes?
3.  The original owner hangs on to just one hex by the end of the battle and thus controls the town?

I cannot find this defined anywhere in the 4th Edition Rules nor is it in the games specific instructions for Invasion 44.