As noted in my comment, never noticed 1/8" before (and am American, so no particular metric bias...). All e.g. MP3 players historically called them 3.5mm jacks, is what my brain is telling me.

Some googling:

3.5mm jack - 49million results

1/8" jack - 63 million results

3.5mm stereo jack - 19 million results

1/8 stereo jack 5.9 million

1/8" stereo jack - 5.47 million

Evidently, it's a common term! Guess once I decided what I was calling them, that's what I searched for, and what I skimmed technical details for.