Re-order format units.

Author: serhiy-storchaka

Doc/c-api/arg.rst

@@ -344,11 +344,10 @@ Other objects
    in *items*.  The C arguments must correspond to the individual format units in
    *items*.  Format units for sequences may be nested.
 
-   If *items* contains format units which store
-   a :ref:`borrowed buffer <c-arg-borrowed-buffer>` or
-   a :term:`borrowed reference`
-   (``y``, ``y#``, ``s``, ``s#``, ``z``, ``z#``, ``S``, ``Y``, ``U``,
-   ``O`` or ``O!``), the object must be a Python tuple.
+   If *items* contains format units which store a :ref:`borrowed buffer
+   <c-arg-borrowed-buffer>` (``s``, ``s#``, ``z``, ``z#``, ``y``, or ``y#``)
+   or a :term:`borrowed reference` (``S``, ``Y``, ``U``, ``O``, or ``O!``),
+   the object must be a Python tuple.
    The *converter* for the ``O&`` format unit in *items* must not store
    a borrowed buffer or a borrowed reference.