In NSW the official proxy form (which must be used) says appointment is for “the purposes of meetings of the owners corporation (including adjournments of meetings).”
That would be all general meetings, Annual or Extraordinary, but lower down there is the qualification where the proxy donor can state the number of meetings or the period that they want covered.
Finally, there is Fair Trading’s own restrictions, which operate regardless of any stated preferences: “The appointment cannot have effect for more than 12 months or 2 consecutive annual general meetings, whichever is the greater.”
You can download a copy of the official form HERE.