Continental Usages
Precisely because there are many traditions and more variation within some of these, there is a plethora of continental coronet types. Indeed, there are also some coronets for positions that do not exist, or do not entitle use of a coronet, in the Commonwealth tradition.
Such a case in French heraldry of the ancien regime, where coronets of rank did not come into use before the 16th century, is the vidame, whose coronet (illustrated) is a metal circle mounted with three visible crosses (no physical headgear of this is type known).
Helmets are often substitutes for coronets, and some coronets are worn only on a helmet.
Read more about this topic: Crown (heraldry)