A group of 120 scholars have signed a letter of complaint over the inclusion of English words in a newly revised Chinese dictionary.

The scholars, including linguists and senior reporters, said the inclusion of words such as the basketball league "NBA" and "PM2.5", a measure of air pollution, violated regulations covering the Chinese language, including the Law on the Standard Spoken and Written Chinese Language.

The 239 English words take up 15 pages in the latest Contemporary Chinese Dictionary, known as the authoritative Chinese-language dictionary.