Coords
The SHAPE and COORDS attributes of A can be used to create client-side image maps via the OBJECT element.
The default SHAPE value is rect, which defines a rectangular region using COORDS="left, top, right, bottom". Other SHAPE values are
default, which specifies the entire image;
circle, which specifies a circular region using COORDS="center-x, center-y, radius";
poly, which specifies a polygonal region using COORDS="x1, y1, x2, y2, ..., xN, yN".
Coordinate values are relative to the top left corner of the object and may be expressed as pixels or percentages. A percentage radius value for circular regions is calculated relative to the smaller of the object's width and height. If two or more regions overlap, the earliest specified region takes precedence.