im with preachers, i have just butted up against this issue. as i said in another thread about this... its absolutely insane that such a thing is possible with FX chains, and NOT FX. also its especially irritating since it takes a fair bit of time when setting up reaper, using the "My Folders" 'feature' of the FX browser, putting hundreds of plugins into custom folders. only to realise that one of the most basic features, the ability to have subfolders/subcategories doesnt exist, and now we have to go through and completely reorganize all FX, and on top of that, bloat up the FX chains catalogue with something that doesnt belong in there.