### 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 Changing the quote characters, for more information.