+Notmuch supports an alternative query syntax based on `S-expressions
+<https://en.wikipedia.org/wiki/S-expression>`_ . It can be selected
+with the command line ``--query=sexp`` or with the appropriate option
+to the library function :c:func:`notmuch_query_create_with_syntax`.
+Support for this syntax is currently optional, you can test if your
+build of notmuch supports it with
+
+::
+
+ $ notmuch config get built_with.sexp_queries
+