Bad value X for attribute “coords” on element “area”: Expected a minus sign or a digit but saw “ ” instead.

The coords value contains a space where the validator expects the start of a number.

An <area> element defines a region in an image map. Its coords attribute describes that region using coordinates in CSS pixels. For shape="poly", provide at least three pairs of x and y coordinates, with an even number of values.

In the example below, Rocket's HTML validator rejects the space immediately after the second comma. Write the coordinates as comma-separated numbers without spaces to avoid this parsing error. Keep the values appropriate for the selected shape.

Invalid example

<map name="floor-plan">
  <area shape="poly" coords="0,0, 100,0,100,50" href="/reception" alt="Reception">
</map>

Valid example

<map name="floor-plan">
  <area shape="poly" coords="0,0,100,0,100,50" href="/reception" alt="Reception">
</map>

Learn more:

MDN Reference

MDN Web Docs: The area element

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WHATWG Spec

HTML Living Standard: Image maps

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