The expression of the task in terms of action is frequently desirable, more especially during an engagement, when tactical considerations are uppermost. Under such circumstances, two or more objectives may be suitable to the appropriate effect desired, but their degree of suitability, and the influence of the factors pertaining to feasibility and acceptability, may vary rapidly with the course of events. In such conditions, an order such as "Attack" without indicating a specific physical objective, may be best calculated to attain desired results, for the reason, more especially, that it affords the subordinate a proper freedom of action. In many cases, the instructions received by a commander will set forth more than one task, often of varying importance. The proper bearing of such a double or multiple task upon his future action is set forth, together with other relevant matters, in the discussion of the mission, which follows. On occasion, a higher commander, in assigning a task, may elect to specify, also, the course of action to be pursued by a subordinate for the attainment of the assigned objective: for example-- "Deny enemy bases in area ABCD by capturing X Island". Here the task is to deny the enemy the use of available bases in the area described; in addition, the higher commander has specified that this be accomplished by the adoption of a predetermined course of action (page 88), expressed in the words "by capturing X Island." Higher authority has in this case made the subordinate's estimate of the situation for him, and has thus arrived at the decision which the subordinate would ordinarily reach for himself. Such procedure may be deemed advisable under certain circumstances: for example, when time is pressing; when a close control of the situation is an important factor; when the qualifications of the subordinate are unknown, as yet doubtful, or known to be inadequate for the operation in hand; or, for various other reasons which may suggest themselves according to the nature of the problem. Occasionally, higher authority, for similar reasons, may also prescribe the action to be taken, in considerable detail. Examples occur during operations of unusual complexity, or when the personnel factors call for special care in coordination of the action. Sometimes, higher authority, instead of announcing both the task and the predetermined course of action, may indicate only the latter; in the example given above, the higher commander would then direct, "Capture X Island". The directive might also include, in some detail, the action to be taken to this end. Procedure such as noted in the foregoing examples involves certain special considerations from the viewpoint of the subordinate. These considerations are discussed hereafter (page 96).