On 2019-08-05 00:18:15 +0800 (+0800), Zhipeng Huang wrote:
> Not quite understand what [GR] stands for
[...]

"Gwoyeu Romatzyh (pinyin: Guóyǔ Luómǎzì, literally "National
Language Romanization"), abbreviated GR, is a system for writing
Mandarin Chinese in the Latin alphabet. The system was conceived by
Yuen Ren Chao and developed by a group of linguists including Chao
and Lin Yutang from 1925 to 1926. Chao himself later published
influential works in linguistics using GR. In addition a small
number of other textbooks and dictionaries in GR were published in
Hong Kong and overseas from 1942 to 2000."

https://en.wikipedia.org/wiki/Gwoyeu_Romatzyh

--
Jeremy Stanley