Now go to:
ACP - Manage forums - Hit the "Delete" icon of the Forum-Link "Testlink"
A "Delete forum" confirmation with the following text comes up:
The form below will allow you to delete a forum and decide where you want to put all topics (or forums) it contained.
Delete forum
Forum name: Testlink
But there are no "topic/posts" possible on a "link"
Maybe the "wording" should be changed if you try to delete a "Forum-Link"...