Allied Telesis AT-S63 - Manual (Page 526)

Chapter 23: Port Security
526 Section IV: Security
Participating
This column applies only when the intrusion action for a port is set
to trap or disable. This option does not apply when intrusion
action is set to No Action (discard). If this option is set to No when
intrusion action is set to trap or disable, the port discards invalid
packets, but it does not send a trap or disable the port.