This read-write TruthValue, when true, causes the port to enter the blocking state upon coming up and, if no BPDU is received within 3 seconds, to automatically transition to the forwarding state. An admin cares because this lets edge ports connected to end hosts (which don't send BPDUs) reach forwarding quickly without needing to be manually marked as edge ports, while still providing a brief safety check. For example, an admin connecting a printer to an access port would rely on this feature so the port forwards traffic within a few seconds instead of waiting through the full STP Listening/Learning delay.