=330.= The principles and methods laid down in the =School of the Trooper= (dismounted and mounted) are, except as may otherwise be indicated, or where clearly applicable only to individual instruction, to be followed in corresponding instruction in the =School of the Squad= and in all subsequent training. The same commands apply unless otherwise stated. Certain modifications in the execution of some of the movements, incident to their use in collective instruction, are noted in appropriate places in the =School of the Squad=. =331.= =Column of twos and of troopers=: Movements, involving the use of column of twos or troopers, although simple in principle, are not adapted to execution as movements of precision, and the details of their execution will be regulated accordingly (pars. 393-400). Familiarity with the practical use of these formations must be insisted upon, but they will be taken in the simplest manner consistent with efficiency in their use. =382.= To avoid repetition the detailed descriptions and explanations of collective movements are, as a rule, based only upon the execution of the mounted movements. =383.= _Gaits for mounted movements._--All mounted movements not specially excepted may be executed at the trot or gallop (par. 239). For the execution of a movement at the =trot or gallop= the command =trot= or =gallop= precedes the command =march= unless marching at the gait desired or unless it be otherwise prescribed. When the indication for the =trot= or =gallop= is included in the command for the movement it precedes the command =march=; thus, 1. =Forward, trot=; 2. =MARCH.= =334.= When the troopers of any element (Def.) move at different gaits, if the gait of such =element= be referred to, the gait of its =base= is to be understood. =335.= A gait is said to be =correspondingly faster or correspondingly slower= than another gait when there is a difference of one degree between the two (par. 239). =336.= In the rules included in pars. 333 to 337 the expression "other elements" (Def.) means in each case elements of the _same kind as the base_. =337.= (_a_) In movements from the halt the base moves at the walk unless another gait be stated in the command or indicated by the leader's movements.