numpy · seberg · Jul 12, 2020 · Jun 1, 2020 · Jun 1, 2020 · Jun 1, 2020
diff --git a/doc/release/upcoming_changes/16476.new_feature.rst b/doc/release/upcoming_changes/16476.new_feature.rst
@@ -0,0 +1,9 @@
+``norm=backward``, ``forward`` keyword options for ``numpy.fft`` functions
+--------------------------------------------------------------------------
+The keyword argument option ``norm=backward`` is added as an alias for ``None``
+and acts as the default option; using it has the direct transforms unscaled
+and the inverse transforms scaled by ``1/n``.
+
+Using the new keyword argument option ``norm=forward`` has the direct
+transforms scaled by ``1/n`` and the inverse transforms unscaled (i.e. exactly
+opposite to the default option ``norm=backward``).
diff --git a/numpy/fft/__init__.py b/numpy/fft/__init__.py
@@ -128,11 +128,17 @@
 Normalization
 -------------
 
-The default normalization has the direct transforms unscaled and the inverse
-transforms are scaled by :math:`1/n`. It is possible to obtain unitary
-transforms by setting the keyword argument ``norm`` to ``"ortho"`` (default is
-`None`) so that both direct and inverse transforms will be scaled by
-:math:`1/\\sqrt{n}`.
+The argument ``norm`` indicates which direction of the pair of direct/inverse
+transforms is scaled and with what normalization factor.
+The default normalization (``"backward"``) has the direct (forward) transforms
+unscaled and the inverse (backward) transforms scaled by :math:`1/n`. It is
+possible to obtain unitary transforms by setting the keyword argument ``norm``
+to ``"ortho"`` so that both direct and inverse transforms are scaled by
+:math:`1/\\sqrt{n}`. Finally, setting the keyword argument ``norm`` to
+``"forward"`` has the direct transforms scaled by :math:`1/n` and the inverse
+transforms unscaled (i.e. exactly opposite to the default ``"backward"``).
+`None` is an alias of the default option ``"backward"`` for backward
+compatibility.
 
 Real and Hermitian transforms
 -----------------------------