Audio over TRS 1/8″ jacks. Is there a standard? – Modular Synthesis Forum

I ask as I’ve noticed gear using TRS mini jacks for audio in and out even though it’s unbalanced mono. The same signal is on tip and ring . I don’t know much about patch cord standards, but various places I have looked have nothing to say on the subject. Obviously, TRS is useful as it can carry stereo but it will also cause a short if a normal TS cord is used (although the driving circuit can be designed to handle a short circuit).
So, is it a standard or just what particular brands decide to do?