Heraldic ordinary
Orle
In heraldry, an orle is a subordinary consisting of a narrow band occupying the inward half of where a bordure would be, following the exact outline of the shield but within it, showing the field between the outer edge of the orle and the edge of the shield.
Text adapted from Wikipedia, CC BY-SA 4.0. Photograph: H. Zell (see Commons), Wikimedia Commons.