Each side's Secretary of War, President, and Vice-President are authorized to transfer men and batteries between that side's units. The CO or XO of the unit that is giving up the regiments or batteries may also submit a transfer order for his unit.
Infantry units may not be raised above 3000 men and one battery, nor below 1500 men. Cavalry units may not be raised above 1500 men and one battery, nor below 750 men. Artillery may not be raised above 400 men and 4 batteries, nor below 200 men and 2 batteries. Militia units may not be raised above 1500 men nor below 500, and may not have batteries. If a transfer order would violate these limits, the order is not carried out. Headquarters units may not transfer men at all. (In unusual cases, ask the GA for a manual intervention.)