Halloween card

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

Construction

• Wide flange beam. From Robert Graysmith's book "Zodiac":

As for the new Zodiac symbol, readers as far away as Detroit wrote to say it represented a Wide Flange Beam, a structural steel shape used in building construction. Some felt that Zodiac was some sort of civil engineer.

Chemistry

• Chemical compound 1-Pentene (scroll down a bit to see the section about pentenes)
  • Image:

Cattle brands

• Red Ryder ranch cattle brand symbol ("flying V F bar")
  • Details
  • Image (the brand appears on the cow in the upper right corner):

• Example of that brand on a live cow:

• Kentucky Ranch brand
  • See bottom of page 32 in this PDF

Excerpt:

Maps / Geography

• Intersection in Vallejo
• Map overlay
• A silhouette of Mount Diablo
  • "An abstraction of the Zodiac's eyes and car headlights emerging from the Diablo mountain range." (source)
• "Diamond sign" from Japanese treasure map

Excerpt:

• Another map overlay example
  • (Image)

Cipher-related

• A method of finding the symbol in Z340
• Mason marks
  • Example from "N!CK"
• Another idea about finding the symbol in Z340

Writing systems / early alphabets

• Bat Creek inscription
  • Apparently a Newsweek article about the Bat Creek Stone was published just one week before the Zodiac mailed the Halloween card (source)
  • Excerpted symbol from the full image:

• Ogham alphabet
• Mike Rodelli proposes the symbol is a combination of the Norse runes Ansuz and Laguz.
  • Ansuz: ᚨ
  • Laguz: ᛚ
• Early Norwegian house marks (bumerker)
• Cooke and Wheatstone codes

Other symbology

• Peace sign interpretation from a draftperson's perspective
  • Image

Names/Monograms

• Nickname/initials of suspect
  • Image