2.1.d Implement and troubleshoot trunking

2.1.d [iv] Manual pruning

With a VLAN disallowed from the trunk, the downstream client switches would not have the VLAN available, hence it would have to be manually added back to the trunk.

Adam, Paul (2014-07-12). All-in-One CCIE V5 Written Exam Guide (Kindle Locations 1630-1632).  . Kindle Edition.