The following lines were added (+) and removed (-):
note: The professional TRS jack can be told apart by the fact that the tip and ring metal parts have a smaller diameter than the sleeve, and TRS plugs often have brass contact surfaces. Stereo jacks are usually nickel-plated, so there is a colour difference too. Forcing the domestic stereo jack plug into a professional TRS socket will often bend the contacts of the socket so it does not make good contact in future when mated with a TRS plug.