This read-write Action scalar sets whether incoming frames matching a special-BPDU rule are discarded or bridged (forwarded normally). Admins configure it to control how the switch handles non-standard bridge protocol data units, for instance from third-party spanning-tree variants, that might otherwise disrupt normal STP operation. For example, an admin dealing with a vendor's proprietary BPDU flooding a segment sets this object to discard so those frames are dropped instead of bridged.