I was thinking of whistling it all away and hoping something would come along to reveal what this mysterious SJ is - so I could pretend I knew all along. But. I am too curious. So, what does it stand for?

book I have on Chinese grammar by some English-speaking teacher of Chinese <---- Want to read! It's so discomfiting to know that grammar *does* exist for Hokkien/Cantonese/whatever, since one has been yammering in one or another for years to (equally) illiterate relatives and friends.