Queue Maintenance checks the REF bit of every frame in each of the Active queues:

    When a page frame's REF bit is off, the PS moves the frame 1 queue to the right …

    Unless the frame is already in the rightmost queue, in which case the PS examines the CHG bit, and:

            If the CHG bit is on, it moves the frame to the Page Out queue;

            If the CHG bit is off, it moves the frame to the Available queue.

    When a REF bit is on, the PS turns it off.