A.1.6 Character Strings
Character strings in Mathematica can contain any sequence of characters. They are input in the form "ccccc".
The individual characters can be printable ASCII (with character codes between 32 and 126), or in general any 8- or 16-bit characters. Mathematica uses the Unicode character encoding for 16-bit characters.
In input form, 16-bit characters are represented when possible in the form \[name], and otherwise as \:nnnn.
Null bytes can appear at any point within Mathematica strings.