h a directive for action along a certain general line,
without prescription of a definite objective, may be especially
appropriate to the situation. Such is the frequent usage in the issue,
for example, of directives of the type known as letters of instruction
(Chapter VIII).

Again, where immediate response is desired, and where the objective
may be understood by implication, the task may be better expressed in
terms of action, rather than of accomplishment. This is frequently the
case where the task is assigned by word of mouth, by memorandum, or by
signal. In the last-named instance, the signal, when it constitutes a
command fully understood by previous usage or experience, may convey a
practically instantaneous comprehension of the objective. In many such
instances, however, an inferred objective will require more analysis.

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
subor