From 2006 GCR:

17.26. OIL CATCH TANKS, FILTERS, AND BREATHERS
Oil holding tanks and engine breathers, whether directly or indirectly
ventilating the crankcase, and all transmission/transaxle breathers shall
be equipped with oil catch tanks. Minimum catch tank capacity shall
be one U.S. quart for the engine and transmission/transaxle.......

my honda transaxle has a small breather tube as noted in:

https://www.hondapartsdeals.com/honda_parts...component=M++02

i don't think i have ever heard this to be an issue but i don't see anything in the IT rules saying that we don't have to comply with this part of the gcr.

and even though "breather vent" is listed as separately from a "vent" in the glossary, they seem to mean the same thing.