Does the guy line attach to the clew or the tack?

The text in the module titled Spinnaker Rigging states, "The tack is the corner attached to the pole. The guy, after being led through the spinnaker pole fitting ... attaches to the tack." But the text later in the module states, "The guy line attaches to the clew and then runs through the end fitting of the spinnaker pole." I assume latter text applies only to, "Larger vessels and the majority of sailing yachts...," but I'm not certain. Do those vessels have two spinnaker poles and two guy lines? If so, how does one distinguish one guy line from the other when communicating with other members of the crew?