Using a male TRS 3.5mm audio connector is something you should do with care. When you hotplug that connector the plug's tip (T) may first make contact with the sleeve (S) of the receptible, then briefly hit the ring (R) until it finally lands on the tip connector. Same goes for the plug ring (R) which may have contact with the sleeve (S) of the receptible.

So expected are:

  T → T
  R → R
  S → S
  

and what can happen briefly is:

  T → S
  T → R
  R → S  
  

Depending on what you're using the connector for, that can ruin your day. Likely this isn't an issue on serial connections, but I have seen people use that connector for power..

On audio systems this is typically not an issue, since tip and ring carry signals that on any gear worth anything should have an output stage that can easily handle a connection to ground.