Fix error wordpress 3.5 “Bad value category tag for attribute rel…”

The wordpress 3.5 release can give you this error: Bad value category tag for attribute rel... The error is give by W3C Validator.
The error can be fix with this changes: editing file wp-includes/category-template.php
Goto line 163 in your category template (wp-includes/category-template.php) file and change this line of source code.

and remove the category include whitespace, so that the line looks like this now:

Save the file and check again with W3C Validator.

Posted in Errors, wordpress 3.5. Tagged with , .