Dynamicdeezign, documentation of html and css
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<area> Client-side image maps
Define a region zone of an image and act as hotspots between tags <map></map>
AREA attribute definitions
-) shape = default|rect|circle|poly
This attribute specifies the shape of a region. Possible values:
default: Specifies the entire region.
rect: Define a rectangular region.
circle: Define a circular region.
poly: Define a polygonal region.
-) coords = coordinates
This attribute specifies the position and shape on the screen. The number and order of values depends on the shape being defined. Possible combinations:
rect: left-x, top-y, right-x, bottom-y.
circle: center-x, center-y, radius. Note. When the radius value is a percentage value, user agents should calculate the final radius value based on the associated object's width and height. The radius should be the smaller value of the two.
poly: x1, y1, x2, y2, ..., xN, yN. The first x and y coordinate pair and the last should be the same to close the polygon. When these coordinate values are not the same, user agents should infer an additional coordinate pair to close the polygon.
Coordinates are relative to the top, left corner of the object. All values are lengths. All values are separated by commas.
-) nohref
When set, this boolean attribute specifies that a region has no associated link.
Attribute to associate an image map with an element
-) usemap = uri
This attribute associates an image map with an element. The image map is defined by a MAP element. The value of usemap must match the value of the name attribute of the associated MAP element.

<area shape="shape" alt="the text" coords="60,60,40" href="http://site.com">
<area shape="shape" alt="the text" coords="60,60,40" href="http://site.com" target="_blank">
<area shape="shape" alt="the text" coords="60,60,40" nohref>

For complete reference see html reference at W3C
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F8..1   F9..1   FA..1   FA..2   FA..3   FA..4   FA..5   FA..6   FA..7   FA..8   FA..9   FA..10   FA..11   FA..12  
FA..13   FA..14   FA..15   FA..16   FA..17   FB..1   FB..2   FB..3   FC..1   FC..2   FD..1   FD..2   FD..3   FD..4  
FD..5   FD..6   FD..7   FE..1   FE..2   FF..1   FF..2   FG..1   FH..1   FI..1   FJ..1   FJ..2   FK..1   FL..1  
FL..2   FM..1   FM..2   FM..3   FM..4   FM..5   FM..6   FM..7   FM..8   FM..9   FM..10   FM..11   FM..12   FM..13  
FM..14   FM..15   FM..16   FM..17   FM..18   FM..19   FM..20   FM..21   FM..22   FM..23   FM..24   FM..25   FM..26   FM..27