Tricky Rules 2

Can players in a side game (like Pennant play) who have completed their game on their rink give advice to players from their side who are still playing on another rink?

Generally this is not allowed.

LAW 44 Designated Manager of Coach

A designated manager or coach of a team or side who has advised the umpire of their name and position before the start of the game, can give advice, but only from outside the boundaries of the green.

LAW 45 Spectators

Spectators or anyone else not directly taking part in a game should not disturb or advise players in any way.