In the novel, the main character, Oedipa Maas, discovers a symbol in a bar bathroom that later appears throughout the novel. It’s a muted trumpet that represents a shadowy organization called Trystero, which may or may not be an underground postal network. The “muted post horn” appears in about a third of the 15 to 20 occurrences of graffiti documented by nine police reports received so far, said Matthew Bowman, the community relations and training officer at the UCSB Police Department.
(The other two-thirds apparently delved into less literary territory through the depiction of male body parts, the F-word and references to the university and the police. For that reason, Bowman said, he doesn’t think the crime is necessarily or completely related to the book.)