9-8-1-g states:
No coach, substitute, athletic trainer or other team attendant shall
act in an unsportsmanlike manner once the officials assume authority for the contest.
Examples are, but not limited to:
The failure of a team to:
1. Be ready to start the first half; and
2. Be on the field following the conclusion of the halftime intermission; or
3. Be ready to start the second half at the conclusion of the mandatory
warm-up period.
Points 1, 2 & 3 are all new this year. In Table 3-1 (TABLE OF GAME CLOCK TIMES) it is stated:
Mandatory Warm-up Period Following Intermission: 3 minutes
(The game officials are responsible for ensuring that there is a
three-minute warm-up period posted on the clock and the clock
immediately started for use by the coaches immediately after the
halftime intermission expires. The head coach is responsible for his
team being on the field for mandatory warm-up time at the end
of the scheduled halftime intermission.)
Hope that helps.