Within mainland China, there has been a persistent drive towards promoting the standard language (); for instance, the education system is entirely Mandarin-medium from the second year onward. However, usage of local dialect is tolerated and socially preferred in many informal situations. In Hong Kong, colloquial Cantonese characters are never used in formal documents other than quoting witnesses' spoken statements during legal trials, and within the PRC a character set closer to Mandarin tends to be used. At the national level, differences in dialect generally do not correspond to political divisions or categories, and this has for the most part prevented dialect from becoming the basis of identity politics.