What do I do about an offence the referee cannot see?

Under Law 6, the other on-field match officials assist the referee with offences when they have a clearer view than the referee. They must also submit a report to the appropriate authorities on any serious misconduct or other incident that occurred out of the view of the referee and the other match officials, and must tell the referee and other match officials that a report is being made.

Timing matters. Under Law 5, a disciplinary sanction (such as a yellow or red card) may only be issued after play has restarted if another match official had identified and attempted to communicate the offence to the referee before play restarted. The restart associated with the sanction does not apply.

Sources: IFAB Laws of the Game 2026/27, Law 6: https://www.theifab.com/laws/latest/the-other-match-officials/ and Law 5: https://www.theifab.com/laws/latest/the-referee/