Pak Sau Gei Noi Moon Paak Sau is not suitable for applying on inner gate. Traditional Writing: 拍手忌內門 http://wingchunlexicon.com/wp-content/uploads/2016/12/PAAK3-SAU2-GEI6-NOI6-MUN4-_mdash-Wing-Chun-Elements_-Glossary.mp3