Methods and apparatus for setting the connection identifier (CID) mask length of a Hybrid Automatic Repeat-Request (HARQ)-MAP or a SUB-MAP pointer information element (IE) in a compressed downlink map (DL-MAP) of an orthogonal frequency-division multiple access (OFDMA) frame are provided in an effort to reduce the number of false indications in the CID mask, while also striving, as a secondary concern, to reduce the CID mask length. In this manner, an individual mobile station (MS) may not waste processing, battery power, or time interpreting a HARQ-MAP message or a sub downlink/uplink map (SUB-DL-UL-MAP) message that was not intended for this particular MS. For some embodiments where the CID mask length is set to be small, the control overhead (i.e., the size of the HARQ-MAP or the SUB-MAP pointer IE) may be decreased, and more of the OFDMA frame may be available for data traffic.