The 802.11h option configured through the radio VAP enables or disables support for 802.11h regulatory information selection.
For the AP, this enables or disables transmission of country IE (Information Element) information in the beacon. Stations supporting 802.11h will configure their regulatory information according to the information in the country IE. The default is enabled.
This would only ever be disabled in certain situations/regions where auto-country selection does not work as desired for particular stations.