set status_away [<text>]
This variable sets the format of the string displayed in the status bar when the client is marked as being away. If the client is not away, nothing is displayed in the status bar.
This value is represented by %A in the STATUS_FORMAT string. The %A has no special meaning in the STATUS_AWAY string itself (it will only expand in STATUS_FORMAT).
Customizing the AWAY indicator on the status bar:
/set status_away (Away)