A WDS whitelist profile contains MAC addresses of neighboring APs allowed to set up WDS links with an AP. After a WDS whitelist profile is applied to an AP radio, only APs with MAC addresses in the whitelist can access the AP, and other APs are denied. In the WDS, only APs with radios working in root mode and middle mode can have a whitelist configured. APs in leaf mode require no whitelist.
For details, see (Optional) Configuring a WDS Whitelist.