There are a number of symbols used to designate a Polyamory relationship. One of the more popular ones is the Trinity symbol. It can stand for a Triad, a Quad, or any other form of relationship. Another popular symbol is the Heart and Infinity symbol. This represents infinite love. This page has Dog Tags with both of those symbols in various forms. We also have Dog Tags with humorous phrases and such.
As with all the other Poly Dog Tags, the link to purchase them is below the image. Each Poly Dog Tag is $15, with $2.00 S&H.