Engrailed and Invected
These lines consist of a series of circular arcs curving in the same direction, meeting at angles, forming points outward (engrailed) or inward (invected). When these terms are applied to a partition rather than to an ordinary, the first part of the field is the "interior".
The arms of Liverpool Hope University include a Cross engrailed of one point on each limb.
The arms of the Pretoria Philatelic Society show a chief engrailed and couped, having the appearance of the edge of a perforated postage stamp.
The arms of Kutlwanong Dorp in South Africa provide an example both of the specification of the number of lobes in invected, and those lobes being trefly.
Read more about this topic: Line (heraldry)