Something I've noticed since the UK and US for sale forums have been merged. Even though you have the tags telling you whether it's US/UK, you can't tell from viewing on the main page. Would it be possible to require that people put [UK] or [US] before the title?
Well, here's one thing - now that we have less diluted forums, it's harder to skim the latest replies just by looking at the forum index. Therefore, I expect people's browsing behaviour will change to actually loading up individual forums rather than just looking at the index. Definitely something we can consider though
They should include a selection box when adding a thread on that forum where you select UK or US. It should then automatically add [US] or [UK] before your title.