F46 is the section or page reference in the honda parts catalog.
looking at that link, F46 in this case is the frame.
Assuming you have the non kalifornia version, the little part on the end of the breather hose snaps in to the frame, this is typical ATV method for honda.
So the next part in the chain would be the frame on page F46.
The kalifornia version has a vapor recovery canister and the hose end has some other type of fitting at the frame.
Probably some supper prevents rust or condensation from getting in the end of the hose with prop 65 cancer warning label attached.
honda used to make paper parts catalogs that had the parts image and a parts list on the facing page.
This is where the F numbers come from, engine parts where on E pages.
I haven't seen these in years.
Cover page of an old catalog I found on line.