public function addInlineType($type, $tag, $index = null)
    {
        if (null === $index || !isset($this->InlineTypes[$type])) {
            $this->InlineTypes[$type] [] = $tag;
        } else {
            array_splice($this->InlineTypes[$type], $index, 0, [$tag]);
        }

        if (strpos($this->inlineMarkerList, $type) === false) {
            $this->inlineMarkerList .= $type;
        }
    }