invis <level>
invis <player>
invis max
invis

  Makes you invisible to anyone below the <level> that you specify, everyone with <player>'s level or below, or if invis max or invis in its own is used, all players with a level lower than yours. You cannot become invisible to users with a higher level than you.

  To become visible again, you can use "invis 0", or the $[vis$] command.