I suggest a preset tag system, with the tags named after the pre-existing boards, so users can select multiple categories to find threads on specific topics.

Let the thread creator select a primary category, deciding which board it goes to, and any tag they chose afterwards will be other boards that the thread may also belong in, but won't be posted to.

I'm sure this will go fairly unnoticed. And I'm positive I will never make this happen, but I hope the site creators come up with a better way to sift through some of this junk.

P.S. Pinned Threads