The string follows the C-style escaping, using the backslash to quote
(escape) the following character(s). Certain letters are translated to
various control codes (e.g. \n, \f, \t, etc.).
x introduces a two character hex code. 0 (the digit zero)
introduces a one to three character octal code (note: an octal byte followed
by a digit must be represented with three octal digits, thus: "\0001"
yielding a NUL byte followed by the ASCII digit 1). Any other character
following the backslash escape is simply inserted, without error, into the
string being formed.
Like ANSI "C", a series of these strings, possibly intermixed with single quote strings, will be concatenated together.