update docs for OAEP
diff --git a/docs/hazmat/primitives/asymmetric/padding.rst b/docs/hazmat/primitives/asymmetric/padding.rst
index 0c2f7ce..06bd2c4 100644
--- a/docs/hazmat/primitives/asymmetric/padding.rst
+++ b/docs/hazmat/primitives/asymmetric/padding.rst
@@ -22,8 +22,8 @@
:param mgf: A mask generation function object. At this time the only
supported MGF is :class:`MGF1`.
- :param bytes label: A label to apply. This is a rarely used field and many
- backends do not support it.
+ :param bytes label: A label to apply. This is a rarely used field and
+ should typically be set to ``None`` or ``b""`` (equivalent values).
.. class:: PSS(mgf, salt_length)