The symbol of a human skull and crossbones was a common sight on medieval pirate flags and now, the Unicode 2620 computer document. Other than these examples, the symbol has been flaunted on cemetery entrances, radiation outposts, and toxic dumps. History of the Symbol The history of the symbol dates back to the 1700s, when the entrances to Spanish cemeteries were marked with actual human skulls and bones. This 'campo santo' practice led to the symbol being associated with death. The sign was engraved on tombstones across Europe. Many crucifixes were designed to feature the symbol beneath the corpus or depiction of Jesus' body. Most of the Christian associations with the symbol come from the mention of the place of Christ's crucifixion as 'Golgotha' or the place of a skull, in the New Testament of the Holy Bible (Mark 15:22). The 1732 Nuestra Señora del Pilar church, that overlooked the Recoleta Cemetery, Buenos Aires, Argentina, was designed to depict the symbol. By the 1800s, the sign was used to label containers of poisonous substances, alongside the 'XXX' symbol. In the nineteenth century, the presence of the symbol on poison bottles became ubiquitous. It was also used by military forces on 'Jolly Roger' submarine flags, reconnaissance battalion emblems and fighter unit aircraft tails. Today the symbol is one of the most recognizable squadron markings. Semantics Behind the Symbol The symbol is indicative of danger and impending harm. Its association with death, poison, and secret societies has resulted in the symbol being recognized as a fraternity and unicode motif. Today, this symbol is commonly associated with references to:

• HTML entity
• Hussars and dragoons
• Nazi SS service
• British lancer regiments
• Los húsares de la muerte, a paramilitary guerrilla group in Chile
• Chetniks or the Serbian royalist and nationalist paramilitaries
• Kuperjanov Partisan Battalion

It thus remains a standard symbol for poison, even beyond industrial usage. It is a sign that environmentally conscious consumers look for. The symbol has been adopted all through the late nineteenth and early twentieth centuries, for various reasons. Business and religious fraternities, secret societies, sororities and even the public domain used the symbol on their badges and logos. As a hazard symbol it warns about the location of toxic material. The symbol is usually accompanied by supplemental information that specifies the nature of the hazard. The use of the symbol has certainly increased since the 1700s. The modern consumer continues to interpret the sign as an indication to 'stay away' from some area or material.