The W3C Validator showing you this error in? WordPress Bad value category tag for attribute rel on element a The string category is not a registered keyword or absolute URL. Whitespace in path component. Use %20 in place of spaces.
For whatever reason they didn’t fix this yet, since i still got this error on the latest WordPress 3.5 release.
There is a little workaround for this by editing file wp-includes/category-template.php
This is exactly what we are doing now:
Goto line 163 in your category template (wp-includes/category-template.php) file:
$rel = ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) ? 'rel="category tag"' : 'rel="category"';
and remove the category include whitespace, so that the line looks like this now:
$rel = ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) ? 'rel="tag"' : 'rel="category"';
We have now a W3 conform rel value in our code and the error should be gone.
Remember: Every time you update your Blog to a newer Revision you have to redo this step again, since the file is getting overwritten.
Check out my Website at: http://ispire.me for more How-To's and IT-related solutions.
My Website is containing following Content: IT Howto, tech secrets, tech helpful hints, openstack, freebsd, debian, smartos, illumos, solaris, windows, kvm, libvirt, pfsense, zfs, nginx, haproxy, varnish, nexentastor e.g.