This is a 16-octet packed list of up to 8 VLAN IDs (two bytes per VLAN) allowed to pass through as a VLAN trunk on an Ethernet port using this service profile, i.e. multiple tagged VLANs are carried transparently over one port rather than being translated or aggregated. Admins use it for business/enterprise service profiles where the customer's own equipment manages multiple VLANs behind a single physical uplink. For example, trunking a business customer's own set of VLANs through one ONU port avoids needing a separate physical port per VLAN.