+
+@node The notmuch Engine
+@subsubsection The notmuch Engine
+
+@table @code
+@item nnir-notmuch-program
+The name of the notmuch search executable. Defaults to
+@samp{notmuch}.
+
+@item nnir-notmuch-additional-switches
+A list of strings, to be given as additional arguments to notmuch.
+
+@item nnir-notmuch-remove-prefix
+The prefix to remove from each file name returned by notmuch in order
+to get a group name (albeit with @samp{/} instead of @samp{.}). This
+is a regular expression.
+
+@end table
+
+