A Gerber file with the outer contour (profile) of the board. This may either be a filled polygon or thin line/arc segments.

If the profile is a filled polygon (Gerber region), then the file should not contain any other objects than the polygon. Cutouts, slots and scoring (v-cut), if any, must be in separate Gerber files.

If lines/arcs are used, they must be consecutive (end location of one segment is the start location of the next segment) and form a closed loop without gaps or overlap.

A file with lines/arcs may also contain lines/arcs for cutouts (which must form closed loops), slot centerlines (which must have the same line width as the slot), and/or scoring (v-cut).