[Mobhack]

Game Guide, section "Scenario Editor", sub section on "Auxiliary troops". Relevant part of the paragraph is highlighted.

Auxiliary troops

These are introduced for user campaign scenarios mainly. Auxiliary troops are best seen as reinforcements given by you, the scenario designer to the player. Auxiliary troops will be added to the player's force, just like support troops, but they are additional to any support points allocated by you for this campaign node. They will appear on the list to be deployed as normal support troops if Aux status (placement hex is then irrelevant). Fixed auxiliary troops (status=fix) will remain in the hex and with the facing you design in the deployment phase, the user cannot move these troops in his deployment, they are useful for troops outside the normal deploy zone, or for critical units you do not want the player to mess with the deployment of, due to your scenario's design.

Cheers
Andy