http://standards-oui.ieee.org/cid/cid.csv.

http://standards-oui.ieee.org/iab/iab.csv.

http://standards-oui.ieee.org/oui/oui.csv.

http://standards-oui.ieee.org/oui28/mam.csv.

http://standards-oui.ieee.org/oui36/oui36.csv.

Record contains information for a organizationally unique identifier (OUI), a 24-bit number that uniquely identifies a vendor, manufacturer, or other organization.

Assignment is either a MAC addresses (most common?), Subnetwork Access Protocol identifiers, World Wide Names for Fibre Channel devices or vendor blocks in EDID.

Registry is an IEEE public OUI listing.