Crown Principality
Drachenwald's Crown Principality of Insulae Draconis is a grandfathered group, existing in an unusual and, this author believes, unique state at the time of this writing (September, 2006). However, other groups have existed as Crown Principalities in the past, including the now kingdoms of Lochac and Ealdormere.
A Crown Principality has no formal existence according to the SCA governing documents. It is essentially a semi-formal declaration of intent to work toward Principality status by a collection of branches that wish to form a principality, but which do not meet one or more of the requirements, usually sufficient numbers. Since it is not a group designation recognized by the SCA, it has no laws, and no formal officers or ceremonial head.
As an adminstrative unit, it may be compared to a region such as those found in the East Kingdom.
However, Kingdom Law and Custom may depute certain powers of the Crown to sub-groups. Thus law and custom may dictate that a Crown Principality have a ceremonial head, such as that of Insulae Draconis, whose heads are styled as Viceroy and Vicereine. Likewise, law and custom may allow those heads to grant non-armigerous awards.