Suggestion: Having a way to check to see if a player is using a trainer would be a great addition to the scripting API.

Possible use cases?
1: Only allow administrators to use trainers, else kick the player.
if(notAdmin(player) && usingTrainer(player) return KickPlayer()

2: On a trainer-allowed server, maybe on the server list have a marker showing that they are using one.

3: If the player is using a trainer, show special messages, or give them access to special commands.

Something like playerelement.usingTrainer; // (read only / returns true-false)
or server.isUsingTrainer(element); // returns true/false