But the filter would only work if people were 100% consistent with putting WTS, WTB or WTT in the thread title.
Most members are good in that respect - but there are always exceptions that would fall through a filter.
Is there some way perhaps of specifying in the thread, like checkboxes, whether it is WTS, WTB, WTT or a combination? If so, a filter would be much easier.
Hmmm ... a quick look, and a lot of the current threads just have FS or FT, and a couple have neither.