Regdomain

A regdomain, in IEEE 802.11 devices, is a regulatory region.

Most mobile wifi devices default to regdomain 0, which means least common denominator settings, i.e. the device will not transmit at a power above the allowable power in any nation, nor will it use frequencies that are not permitted in any nation.

The regdomain setting is often made difficult or impossible to change so that the manufacturer does not get in trouble with a regulatory agency like the Federal Communications Commision.