AMA Rulebook:
2.13 On-Track Regulations
a. No rider may, at any time, ride in such a manner as to endanger
life or limb of other riders, AMA Pro Racing or the public.
b. Any rider, participant or team that intentionally engages in
activities, including by way of example but not limitation,
avoidable contact, with the consequence negatively impacting
a competitor’s performance will be subject to one of the following
penalties: disqualification from the current session, gridding at
the back of the field, loss of championship points, disqualification
from the event, suspension. Further official action will be at the
discretion of AMA Pro Racing.