This is from the CCA Manual, Part 3, Section 5.2:
A. Warnings for Delay
1. The administering official shall blow the whistle and, near or on the spot of the infraction, verbalize that a warning is being issued to the specific team and player (if applicable) for a particular type of delay. For example, “Warning on red No. 12 for interfering with the ball after a goal.”
2. Inform the official scorer of the warning to be placed in the scorebook. The information recorded should include the team, player (if applicable), type of delay warning, half and game time. That information may be relayed to the official closest to the table, who then communicates it with the scorer.
3. A member of the crew should then inform the head coach of the specific warning. It is preferred that the closest official inform the head coach, unless detailed information from the administering official is essential to convey.