re: Line of scrimmage question

The exact wording as follows:

Lineman and Back
ARTICLE 4. a. Any Team A player in one of the following positions is a
lineman.
1. A lineman is any Team A player legally on his scrimmage line when
the ball is snapped. An interior lineman is any Team A player
legally
on his scrimmage line and positioned between the end Team A players
who are also on the line of scrimmage at the snap. An ineligible pass
receiver of Team A is “on his scrimmage line’’ at the snap when he
faces his opponent’s goal line with the line of his shoulders parallel
thereto and his head breaking the plane of the line drawn through the
waistline of the snapper.
RULE 2-27 / DEFINITIONS FR -57
2. An eligible pass receiver of Team A is “on his scrimmage line’’ at
the snap when he faces his opponent’s goal line with the line of his
shoulders approximately parallel thereto and his head breaking the
plane of the line drawn through the waistline of the snapper.
3. A Team A player also is a lineman when, after the ball is ready for
play and the snapper touches or simulates (hand[s] at or below his
knees) touching the ball, his head breaks the plane of the line drawn
through the waistline of the snapper (Exception: Rule 7-1-3-b-1).
b. A back is any Team A player whose head or body does not break the
plane of the line drawn through the rear-most part, other than the legs
or feet, of the nearest Team A player (except the snapper) on the line of
scrimmage when the ball is snapped. A lineman becomes a back before
the snap when he moves to a position as a back and stops (A.R. 2-27-
4-I)