This blog relates to a conversation I had with Sifu Chu regarding the Shaolin temple in Southern China. His teacher Go Lo Tin was a lay priest from this temple and so it is a direct oral transmission.
Within the temple there were various chambers where a student would study with a teacher. Unlike the movies, progress was not through the chambers, but to stay within the one and learn everything the teacher had to offer. The student would be allocated to a teacher depending on body type, attitude and also to the needs of the temple and the people it served. The various teachings would be in weapons and empty hand, with the pole being the main weapon taught and the various animal styles would be studied.
After graduating the student could stay or leave. If he chose to leave it would be through a red door and the student would return to the world to help others, as they would also have studied healing as well as martial arts.
The significance of the red door is why the style is called Chu Gar Hung Kuen, Chu Family Red Boxing. It honours the Emperor Chu Hung Mo and the Shaolin temple.