This read-write object, used by classifiers within the Diffserv Rules table, lets the classifier apply to all Diffserv boundary ports or all Diffserv interior ports collectively rather than to the single port named in rlPolicyClassifierInIfIndex, which is only used when this field is set to 'normal'. An admin uses this to write one classifier rule that automatically covers an entire class of ports (boundary vs. interior) instead of configuring a separate rule per port. For example, an admin implementing Diffserv boundary marking policy would set this to allBoundary so the single classifier applies uniformly to every boundary-facing port rather than needing one entry per port.