[phoenix0001]

All items, weapons, melee, etc., all can add a message prompts, players pick up an item there will be a prompt to tell the player the function of this item and the special usage.

For example:
grenade_launcher
you can continuously hit the maximum 9 bullets.
https://forums.alliedmods.net/showthread.php?p=1495171

pumpshotgun
Missile System Can launch missiles
https://forums.alliedmods.net/showthread.php?t=136019