  
  * Support for the pre-Django 3.1 ``django.core.signing.Signer`` signatures
    (encoded with the SHA-1 algorithm) will be removed.
  
  * Support for the pre-Django 3.1 user sessions (that use the SHA-1 algorithm)
    will be removed.
  
  * The ``get_request`` argument for
    ``django.utils.deprecation.MiddlewareMixin.__init__()`` will be required and
    won't accept ``None``.
 
</s> remove * The default :class:`django.core.signing.Signer` algorithm is changed to the
  SHA-256. Support for signatures made with the old SHA-1 algorithm remains
  until Django 4.0.
 </s> add * The default algorithm of :class:`django.core.signing.Signer`,
  :meth:`django.core.signing.loads`, and :meth:`django.core.signing.dumps` is
  changed to the SHA-256. Support for signatures made with the old SHA-1
  algorithm remains until Django 4.0. </s> remove     Returns URL-safe, sha1 signed base64 compressed JSON string. Serialized
    object is signed using :class:`~TimestampSigner`.
 </s> add     Returns URL-safe, signed base64 compressed JSON string. Serialized object
    is signed using :class:`~TimestampSigner`.
* Support for the pre-Django 3.1 ``django.core.signing.dumps()`` signatures
  (encoded with the SHA-1 algorithm) in ``django.core.signing.loads()`` will be
  removed.

  
  * Support for the pre-Django 3.1 ``django.core.signing.Signer`` signatures
    (encoded with the SHA-1 algorithm) will be removed.
  
* Support for the pre-Django 3.1 ``django.core.signing.dumps()`` signatures
  (encoded with the SHA-1 algorithm) in ``django.core.signing.loads()`` will be
  removed.

  * Support for the pre-Django 3.1 user sessions (that use the SHA-1 algorithm)
    will be removed.
  
  * The ``get_request`` argument for
    ``django.utils.deprecation.MiddlewareMixin.__init__()`` will be required and
    won't accept ``None``.
keep keep keep add keep keep keep keep keep keep
 Refs #27468 -- Added tests and release notes for signing.dumps()/loads() changes.

Follow up to 71c4fb7beb8e3293243140e4bd74e53989196440. 
docs/internals/deprecation.txt