Can somebody tell me more about this form? I've found it in the Southern Mantis and Southern Great Ancestor systems. There should also be a YongChun White Crane form by that name which I can't find.
TaiZu Xiao Si Men
https://www.youtube.com/watch?v=bUcBVukwZNQ
Southern Praying Mantis Say Mun Sau
https://www.youtube.com/watch?v=uYLY4jlMeGw
http://www.youtube.com/watch?v=7Kot9OSrvAM
Hakka Kuen 四門
http://www.tudou.com/programs/view/6qOJQvNZHr8
Fujian Luohan SiMen / SeiMun
https://www.youtube.com/watch?v=53EZkHu_Pho
https://www.youtube.com/watch?v=VNnJM1bUQOo
WingChun (Chan Wah Shun, Chan Yu Min lineage) SilLin SeiMun
https://www.youtube.com/watch?v=B1RlwzKAcnI
Hung Gar Sei Mun
https://www.youtube.com/watch?v=5l5FX8hj_fA
Pak Mei Sei Moon Baat Gwa Kuen
https://www.youtube.com/watch?v=WGr35kPHe-k
Choy Lee Fut 四門拳
https://www.youtube.com/watch?v=jcd7WgLY9Nw
Uechi Ryu Seisan
https://www.youtube.com/watch?v=TUCdg0hEy6Q
Chotoku Kyan Seisan
https://www.youtube.com/watch?v=z2xiW8dHc7o
GoJu Ryu Seisan
https://www.youtube.com/watch?v=LJeOCRV0oF0
Shotokan Hangetsu
https://www.youtube.com/watch?v=3gfKxxBnEcE