Most gender specific language
Who
Nüshu
Where
China Mainland (Western Hunan, a poor province South of Yangtse.)
When
959

For about 1000 years in a region of the Hunan province, China, nüshu ("women's writing") has been used exclusively by women to communicate their deeper feelings to other women. It is thought that it was invented by the concubine who belonged to an emperor of the Song dynasty (960-1279).

Study of the scripts did not begin until 1950 but soon after had to be abandoned due to the Chinese Cultural revolution. When research began again in 1980, only about a dozen women could read nüshu and only three could write it. All nüshu material, including letters and wedding congratulations, is written in verse. Men played no role in the production or dissemination of its writings and it was often used to write stories that challenged the conventional male morality.