3.2 Quoting input to m4

A quoted string is a sequence of characters surrounded by quote strings, defaulting to ‘`’ and ‘'’, where the nested begin and end quotes within the string are balanced. The value of a string token is the text, with one level of quotes stripped off. Thus

`'
⇒

is the empty string, and double-quoting turns into single-quoting.

``quoted''
⇒`quoted'

The quote characters can be changed at any time, using the builtin macro changequote. See section Changing the quote characters, for more information.