Document the new interface
diff --git a/docs/hazmat/backends/interfaces.rst b/docs/hazmat/backends/interfaces.rst
index 63f8406..42dba72 100644
--- a/docs/hazmat/backends/interfaces.rst
+++ b/docs/hazmat/backends/interfaces.rst
@@ -578,6 +578,23 @@
:class:`~cryptography.hazmat.primitives.interfaces.EllipticCurvePublicKey`
provider.
+.. class:: PEMSerializationBackend
+
+ .. versionadded:: 0.6
+
+ A backend with methods for working with any PEM encoded keys.
+
+ .. method:: load_pem_private_key(data, password)
+
+ :param bytes data: PEM data to load.
+ :param bytes password: The password to use if the data is encrypted.
+ Should be ``None`` is the data is not encrypted.
+ :return: A new instance of the appropriate type of private key that the
+ serialized data contains.
+ :raises ValueError: If the data could not be deserialized.
+ :raises cryptography.exceptions.UnsupportedAlgorithm: If the data is
+ encrypted with an unsupported algorithm.
+
.. class:: TraditionalOpenSSLSerializationBackend
.. versionadded:: 0.3
@@ -592,8 +609,8 @@
:param bytes password: The password to use if this data is encrypted.
Should be None if the data is not encrypted.
- :return: A new instance of the appropriate private key or public key
- that the serialized data contains.
+ :return: A new instance of the appropriate type of private key that the
+ serialized data contains.
:raises ValueError: If the data could not be deserialized correctly.