您可以展开KSE允许的标记列表（及其属性）：

add_filter(\'wp_kses_allowed_html\', \'wpse_283385_blocktip_tag\');
function wpse_283385_blocktip_tag($allowed_tags) {
    $allowed_tags[\'blocktip\'] = array(
        \'name\' => true,
        \'id\' => true,
        \'class\' => true,
        \'style\' => true
    );

    return $allowed_tags;
}

add_filter(\'tiny_mce_before_init\', \'wpse_283385_blocktip_tag_tinymce\');
function wpse_283385_blocktip_tag_tinymce($init) {
    $tags = \'blocktip[*]\';

    if ( isset( $init[\'extended_valid_elements\'] ) ) {
        $init[\'extended_valid_elements\'].= \',\'.$tags;
    } else {
        $init[\'extended_valid_elements\'] = $tags;
    }

    return $init;
}