A skull was the symbol of the Nazi SS..........Sainte S church mentioned in the Da Vinci Code....which has an actual real meaning.........skull and bones....a US secret society..

Uniforms and insignia of the Schutzstaffel - Wikipedia

https://en.wikipedia.org/wiki/Uniforms_and_insignia_of_the_Schutzstaffel

The uniforms and insignia of the Schutzstaffel were paramilitary ranks and uniforms used by the ... The SS can trace its origins to several early Freikorps and Nazi Party formations, among them the ..... The ancient jawless Danziger style of Totenkopf was gradually replaced by the 'classic' SS skull, a naturalistic d