For clarity's sake:

Dai Lien Tao (Da Lian Tou) is one of the 12 sets (short series of movements) taught by Leung Jan to his Gulao, Heshan, Guangdong students after he retired and moved back there from Foshan (where he taught Chan Wah-Shun, Yip Man's sifu).

Dai Nim Tao (Da Nian Tou) is the name Lee Shing used to refer to all 12 of the sets.

Lien and Nim are different characters with different meanings.