This article is from the Polyamory FAQ, by email@example.com (H. Wilper) with numerous contributions by others.
Not that I know of. ;-) There are several proposed symbols, of
which the most common seems to be the parrot. As parrot pins and
other ornaments are relatively easy to find, this symbol seems
likely to catch on over the others. It also has the advantage of
being humorous, which is a needed quality in such a staid,
conservative group as alt.poly. (Joke, folks! Set irony filters