Sydney is mostly a girls' name, but it is used for boys 4.31 percent of the time.
The Sigil of Lucifer, the symbol of Satan. A sigil is a magical symbol, a symbol believed to hold connections to a greater supernatural power. Sigils are often related to Religion.
But if you are looking for a potted history of sigils then it really depends on how you define the term. You could go all the way back to Neolithic cave art and say that those squiggles were designed to bring about some kind of real-world effect could be considered sigils.