Create Custom WordPress User Roles

    // To add the new role, using 'international' as the short name and
    // 'International Blogger' as the displayed name in the User list and edit page:
  
    add_role('international', 'International Blogger', array(
        'read' => true, // True allows that capability, False specifically removes it.
        'edit_posts' => true,
        'delete_posts' => true,
        'edit_published_posts' => true,
        'publish_posts' => true,
        'edit_files' => true,
        'import' => true,
        'upload_files' => true //last in array needs no comma!
    ));
   
     
    // To remove one outright or remove one of the defaults:
    /*
    remove_role('international');
    */

 

WordPress limit Comment Length

add_filter( 'preprocess_comment', 'jeba_wp_comment_length' );

function jeba_wp_comment_length($comment) {
if ( strlen( $comment['comment_content'] ) > 4000 ) {
wp_die('Comment is too long. Please keep your comment under 4000 characters.');
}
if ( strlen( $comment['comment_content'] ) < 90 ) {
wp_die('Comment is too short. Please use at least 90 characters.');
}
return $comment;
}

Note: Here can change comment length 4000 and 90 characters.