Wordpress: Query Posts without allocated taxonomies
问题 I would like to filter all post queries by a specific term of a custom taxonomy (specified by an url). Currently I'm using add_filter('request', ...) and 'tax_query', which kind of works now. So I get all posts of this term, but I would like to get those posts, which do not have ANY terms allocated of this taxonomy. I was trying something like: $request['tax_query'] = array( 'relation' => 'OR', array( 'taxonomy' => 'brand', 'field' => 'slug', 'terms' => array( $term ) ), array( 'taxonomy' =>