+``(infix`` *atom* ``)``
+ Interpret *atom* as an infix notmuch query (see
+ :any:`notmuch-search-terms(7)`). Not supported inside fields.
+
+``(matching`` |q1| |q2| ... |qn| ``)`` ``(of`` |q1| |q2| ... |qn| ``)``
+ Match all messages have the same values of the current field as
+ those matching all of |q1| ... |qn|. Supported in most term [#not-path]_ or
+ phrase fields. Most commonly used in the ``thread`` field.
+
+``(regex`` *atom* ``)`` ``(rx`` *atom* ``)``
+ Interpret *atom* as a POSIX.2 regular expression (see
+ :manpage:`regex(7)`). This applies in term fields and a subset [#not-phrase]_ of
+ phrase fields (see :any:`field-table`).
+