RFC1843 deals with mixing Chinese and ASCII characters in messages. In essence, RFC1843 switches between ASCII and Chinese by doing this:
This sentence is in ASCII.
The next sentence is in GB.~{<:Ky2;S{#,NpJ)l6HK!#~}Bye.
Simple enough, and widely used in China.
The following functions are available to handle this encoding:
rfc1843-decode-regionrfc1843-decode-string