Syntax of attribute value does not conform to declared value

Cause:

The value of an attribute contained something that is not allowed by the specified syntax for that type of attribute. For instance, the “selected” attribute must be either minimized as “selected” or spelled out in full as “selected="selected"”; the variant “selected=""” is not allowed.

Example:

<option value="Wild Dogs" selected="">Wild Dogs</option>

<option value="Wild Dogs" selected="selected">Wild Dogs</option>

Solution:

Spell the attribute out in full.

References:

• W3 validator: http://validator.w3.org/