[clreq] Mainland Chinese parentheses ? (#252)

r12a has just created a new issue for https://github.com/w3c/clreq:

== Mainland Chinese parentheses ? ==
https://w3c.github.io/clreq/#id81
Parentheses.

After describing the characters used for Taiwan for parentheses, the text simply says the following:

> General Rules for Punctuation (GB/T 15834–2011), the national standard issued by China Central Government, lists em dash as one type of dash.

Is that in the right place?  Does it mean to say 'as one type of parenthesis'?? Is the description of parens for Mainland missing? (Note that there's a section about EM-dash immediately after.)

Please view or discuss this issue at https://github.com/w3c/clreq/issues/252 using your GitHub account