Lamen is a general term for a magical pendant worn around the neck so that it hangs upon the breast over the heart. Its uses vary but generally is a commandment of authority and a grade of magician, anon. The magician wears a lamen which is a symbolic representation of his relation to his godhead. He will wear lamens made of the sigils of spirits he wishes to command. It has been described as "a sort of Coat of Arms. It expresses the character and powers of the wearer." One type of lamen is the talisman which functions as a storehouse of some particular kind of energy, the kind that is needed to accomplish the task for which you have constructed it.
The Pentacle is often confused with both the others; it is also called a "Minutum Mundum", "the Universe in Little".
Various Magical Orders used Lamen, including Ordo Templi Orientis and Hermetic Order of the Golden Dawn. They were used to mark members just as secret handshakes have been used throughout the ages.
Lamen are also used by magicians to invoke certain spirits of the Key(s) of Solomon. The Book of Abramelin is said to have been written by Abraham of Worms as a letter to his son Lamech and contains specific instructions on how to use the "greater Key of Solomon". It is said that the following people of the Bible knew the "greater Key of Solomon": Abraham, Moses, Aaron, David, and Solomon.