[BirdOPrey5]

The quick answer is you don't... By default you can only use one set of thread icons per style, you can't customize them for each forum.

Your thread icons are controlled by the path Item Status Icon Folder in your "All Style Options" for each style.

You'd have to copy the forum icons and rename them to the appropriate thread icon names.

If you really wanted to have separate thread icons for each forum then you'd have to make a unique style for each forum and in your forum manager set a specific style for each forum- this could easily get messy and would mean you really couldn't have users select any styles, they'd all be set by you.

I suppose a mod could be made to add a feature with unique thread icons for selected forums, but I haven't seen one before.