"The intent of this rule was and is to allow receivers to run unimpeded pass routes after five yards, and it is the conclusion of the [competition] committee that the present enforcement of the rule is not consistent with the intent.
"Accordingly, the committee has determined that a simple clarification of the rule . . . and a re-emphasis of its enforcement will allow the rule to be officiated as it was intended. A defender is not permitted to chuck or extend an arm or to hook the receiver, if it re-directs, restricts or impedes the receiver 'in any way.' However, incidental contact (not intentional) is permissible.
"This rule will be strictly enforced. Defensive players who initiate contact beyond five yards by use of the squat or collision techniques will be penalized.''
Source: 2004 Officiating Department Presentations to Media and Networks