+*Modifiers* refer to any prefixes (first elements of compound queries)
+that are neither operators nor fields.
+
+``(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`).
+
+``(starts-with`` *subword* ``)``
+ Matches any term starting with *subword*. This applies in either
+ phrase or term :any:`fields <fields>`, or outside of fields [#not-body]_. Note that
+ a ``starts-with`` query cannot be part of a phrase. The
+ atom ``*`` is a synonym for ``(starts-with "")``.
+