Mercury documents may consist of the following octets:
* 0x0a (newline)
* 0x0d (carriage return)
* 0x20-0x7e
0x20 - 0x7e is the range of so-called printable characters in 7-bit ASCII. [a-z][A-Z][0-9], space, and some punctuation. That would seem to exclude several human languages.