Bring back text about unsupported formats
diff --git a/docs/hazmat/primitives/asymmetric/serialization.rst b/docs/hazmat/primitives/asymmetric/serialization.rst
index f0f18fd..9ca493a 100644
--- a/docs/hazmat/primitives/asymmetric/serialization.rst
+++ b/docs/hazmat/primitives/asymmetric/serialization.rst
@@ -223,6 +223,10 @@
     Deserialize a public key from OpenSSH (:rfc:`4253`) encoded data to an
     instance of the public key type for the specified backend.
 
+    .. note::
+
+        Currently Ed25519 keys are not supported.
+
     :param bytes data: The OpenSSH encoded key data.
 
     :param backend: A backend providing