UBB.threads PHP Forum Software Community Forums Resources and Customizing How Do I? Is there a way to add unique content islands to specific forums?

There's no reason why you couldn't start assigning IDs to your content islands via javascript in your content island (find the grandparent node and set its ID), then use CSS styling in your forum header includes to hide or display that ID.

It wouldn't actually stop the content island being generated and sent to the browser, but would stop it being displayed there.