Question

Is there any way to turn off “permalinks” only for tags in WordPress?
I’d like to keep the ?tag= structure and have the tags displayed without slashes, but also keep post and page URLs with nice permalinks.

For example:
With permalinks on I’d like to have tag linked like this: ?tag=carrot instead of /tag/carrot/

The reason for doing this is a bit long and complicated, but if you think it is relevant, I might include it in the replies.

Answer 1

You can use the term_link filter in WordPress, which filters the URL for any of the term links (tags, categories, custom taxonomies) to just change the links for tags to use the query instead of the permalinks. Adding the following to a plugin or your theme’s functions.php file should do the trick.

function filter_tag_link($taglink, $tag, $taxonomy) {
    if ('post_tag' == $taxonomy) {
        $taglink = '?tag='.$tag->slug;
    }  
    return $taglink;
}

add_filter('term_link', 'filter_tag_link', 10, 3);

There is no useful documentation yet for term_link filter on the WordPress Codex, but looking at the source may help if you want to explore further.