Even though "mutt," "dog," and "perro" refer to the same thing, their relationships must be explicitly specified.

A single concept could have an English preferred label of "dog," a Spanish preferred label of "perro," and a French preferred label of "chien."

Another disadvantage of this arrangement is that the terms "mutt" and "perro" are as separate from "dog" as the term "cat" or "gato" (a Spanish term).