If your unit wins the close combat but the enemy does not flee, or the combat was a draw, your unit can immediately make a combat reform manoeuvre.
A combat reform is essentially a standard reform save for the fact that the centre point of the reformed unit does not have to stay in the same place. The most common usage of a combat reform is to allow the unit to turn to face its enemy (if attacked in the flank or rear), although it can also be used to bring more models into the fight by increasing the unit's frontage. There are three special restrictions on a combat reform, however:
The unit may not reform to get a model (friend or foe) out of base contact with the enemy if it was in contact before the reform was made.
The unit may not reform in such a way as to contact a different facing on any enemy unit it is in contact with, though the model can be in base contact with a different enemy at the end of the reform if you wish.
The unit must keep its front arc in base contact with an enemy unit.