Non-standard varieties of Standard Mandarin are a byproduct of the long and strenuous process that led to the emergence of a codified standard language in China. Even after the issue of the variety to be chosen as the ‘standard’ for the national language was settled, for a large number of its speakers this variety of Chinese was a second language. Interference from the native language naturally gave birth in some areas to local varieties diverging to some extent from the new standard.

One of these non-standard varieties was called Lánqīng Guānhuà 藍青官話, literally 'blue-green Mandarin'…