Add note about the version constraint of this PR

README.rst

@@ -14,6 +14,12 @@ want to use this feature you must install both the ``default`` and the ``geo``
 profile in your policy (the  ``geo`` profile won't install the  ``default``
 profile).
 
+Since `1.2.1` the zoomlevel and maplayer defined in the addressblocks edit panel
+is saved. However, this will only work together with `ftw.simplelayout` versions
+`2.0.3` and `1.23.10` (backport) or higher. For more information see
+`ftw.simplelayout#530 <https://github.com/4teamwork/ftw.simplelayout/pull/530>`_
+and `ftw.addressblock#25 <https://github.com/4teamwork/ftw.addressblock/pull/25>`_.
+
 There is an extra ``contact`` which will provide a contact form. If you
 want to use this feature you must install both the ``default`` and the ``contact``
 profile in your policy (the  ``contact`` profile won't install the  ``default``