Halloween card
Contents
Description
This symbol appeared in the card Zodiac sent to Paul Avery on Oct 27, 1970. It also appeared on the envelope the card came in.
Interpretations and comparisons
Chemical compound 1-Pentene
Details (scroll down a bit to see the section about pentenes)
Red Ryder ranch cattle brand symbol ("flying V F bar")
Image (the brand appears on the cow in the upper right corner):