The read syntax for a string is a double-quote, an arbitrary number
of characters, and another double-quote,
"like this". To
include a double-quote in a string, precede it with a backslash; thus,
"\"" is a string containing just one double-quote
character. Likewise, you can include a backslash by preceding it with
another backslash, like this:
"this \\ is a single embedded
The newline character is not special in the read syntax for strings; if you write a new line between the double-quotes, it becomes a character in the string. But an escaped newline—one that is preceded by ‘\’—does not become part of the string; i.e., the Lisp reader ignores an escaped newline while reading a string. An escaped space ‘\ ’ is likewise ignored.
"It is useful to include newlines in documentation strings, but the newline is \ ignored if escaped." ⇒ "It is useful to include newlines in documentation strings, but the newline is ignored if escaped."