Doubt about grounding - IRB Laws of Rugby Union 2012

Definitions
22.1

Grounding the ball
22.2

Picking up the ball
22.3

Ball grounded by an attacking player
22.4

Other ways to score a try
22.5

Ball grounded by a defending player
22.6

Scrum, ruck or maul pushed into in-goal
22.7

Restarting after a touch down
22.8

Ball kicked dead through in-goal
22.9

Defending player in in-goal
22.10

Ball held up in-goal
22.11

Ball dead in in-goal
22.12

Ball or player touching a flag or flag (corner) post
22.13

Attacking infringement with scrum sanction
22.14

Defending infringement with scrum sanction
22.15

Doubt about grounding
22.16

Infringements in in-goal
22.17

Misconduct or unfair play in in-goal

22.15 DOUBT ABOUT GROUNDING

If there is doubt about which team first grounded the ball in the in-goal, play is re-started by a 5-metre scrum, in line with the place where the ball was grounded. The attacking team throws in the ball.