This command lets you use items and potions that you may be carrying.
Healing potions add to your HP, as if you used the HEAL command.
HP Potions, however, add to your maximum HP possible.
Strength and defense potions add to their respective values.

SYNTAX: /msg %S USE {HEALING | STRENGTH | DEFENSE | HP}
Example: /msg %S USE HEALING
Example: /msg %S USE STRENGTH
Example: /msg %S USE DEFENSE
Example: /msg %S USE HP