Some examples of possible uses:
- Different secret-found sounds/messages for different player classes (Demonsteele and Samsara use a gross "if secrets found this tic > secrets found last tic..." ACS trick to try and do this, but it doesn't work especially well in multiplayer since it triggers for every player simultaneously)
- Printing the message to a suitable part of the HUD (ex. for a Doom Alpha-style helmet HUD with its own message display)
- More complex secret rewarding (ex. giving the player points for triggering a secret, telling other players that a specific player has found a secret)