To guard against a flank attack or an enveloping attack the captain may detach a platoon to move to the threatened flank so as to take an enveloping attack in flank or meet a flank attack. If a flank platoon be so designated, it acts on the corresponding flank unless otherwise directed. When no platoon is specially designated for flank guard, the corresponding duties fall upon the reserve. =643.= The captain's commands should include an indication of the objective, unless the latter is obvious, designate the elements of the attack, and state any special mission that is assigned to any element. The captain's orders also usually include an indication of the weapon to be used by the several elements of the attack and may prescribe the formations to be employed. All details not prescribed by the captain are left to the discretion of the commanders of the several elements into which the attack is divided. Where the same weapon is to be used by all it is ordinarily drawn at the captain's orders before the instructions for the attack are given. Otherwise, each commander gives the proper orders for drawing saber or raising pistol. =644.= The troop being, for example, =in line=, marching at a gallop with sabers drawn, the captain may command: =Objective, Cavalry in front; Second and Third platoons, to the charge; First platoon, flank attack; Fourth platoon, reserve.= Each element of the attack proceeds at once to carry out its orders. The leader of the attacking line (whether the captain or a lieutenant) directs the leader of the base platoon to close on him before charge is ordered (par. 563). In other respects, the charge is conducted as explained for the platoon (pars. 562-564). The troop being, for example, in column of platoons, marching at a gallop, no weapon drawn, the captain may command (the objective being obvious): =First and Second platoons, pistol attack; Third platoon, reserve; Fourth platoon, left flank guard.= The leader of the attacking line commands: 1. =As foragers=, 2. =MARCH=, and attacks with the pistol according to the principles explained for the platoon (pars. 566-568) as soon as the second platoon completes its deployment on the left of the first platoon. The commanders of the third and fourth platoons move to their positions, drawing saber or raising pistol in their discretion. Should the captain command, for example: =First and Second platoons, pistol attack in two lines; Third platoon, charge enemy's right flank; Fourth platoon, reserve=, the third platoon may charge with the saber. Should the captain cause pistols to be raised before ordering the attack all use the pistol. The above are only examples to indicate the character of the captain's commands. The actual orders must meet the situation presented.