This read-create object specifies the C-TAG VLAN ID to be pushed or swapped onto frames at this flow point, applicable for push, swaptag, swapvid, and pushvid control types per the description. Admins set this VLAN ID when the flow point needs to add or replace a customer-tag VLAN identifier as traffic passes through, which is central to how VLAN-based service delineation works. For example, provisioning a service that pushes a specific customer VLAN tag onto untagged incoming frames requires setting this object to that VLAN ID.