3. (a) In all races run in lanes, each athlete shall keep within his allocated lane from start to finish. This shall also apply to any portion of a race run in lanes.(b) In all races (or any part of races) not run in lanes, an athlete running on a bend, on the outer half of the track as per Rule 163.5(b), or on any curved part of the diversion from the track for the steeplechase water jump, shall not step or run on or inside the curb or line marking the applicable border (the inside of the track, the outer half of the track, or any curved part of the diversion from the track for the steeplechase water jump). Except as stated in Rule 163.4, if the Referee is satisfied, on the report of a Judge or Umpire or otherwise, that an athlete has infringed this Rule, he shall be disqualified.
4. An athlete shall not be disqualified if he (a) is pushed or forced by another person to step or run outside his lane or on or inside the curb or line marking the applicable border, or (b) steps or runs outside his lane in the straight, any straight part of the diversion from the track for the steeplechase water jump or outside the outer line of his lane on the bend, with no material advantage thereby being gained and no other athlete being jostled or obstructed so as to impede his progress. If material
advantage is gained, the athlete shall be disqualified.
Note: Material advantage includes improving his position by any means, including removing himself from a “boxed” position in the race by having stepped or run inside the inside edge of the track.