How do I create custom tags for WordPress SEO? [closed]

Just look to plugin…

There is a hook filter for replacements wpseo_replacements, so code can look something like this…

add_filter('wpseo_replacements', 'city_wpseo_replacements');
function city_wpseo_replacements($vars){
    $vars['%%city%%'] = 'some city';
    return $vars;       
}