The argot of the underworld is difficult to understand.
In Paris argot the men of these six central brigades are nicknamed "vaisseaux" (vessels), because they carry on their collars the badge of the city of Paris - an ancient ship - while the sergeants in the town districts wear only numbers, their own individual number, and that of the quarter in which they serve.
Argot, a cock's spur), which are violet-black or dark-purple externally, and whitish with a tinge of pink within, are between 3 and 12 in.