diff --git a/docs/html/user_guide.rst b/docs/html/user_guide.rst
index 2c2b4725a..fede33db6 100644
--- a/docs/html/user_guide.rst
+++ b/docs/html/user_guide.rst
@@ -1064,6 +1064,12 @@ incompatible or inconsistent requirements combinations, now's a good
time to fix the underlying problem in the packages, because pip will
be stricter from here on out.
+We are also changing our support for :ref:`Constraints Files` :
+
+* Unnamed requirements are not allowed as constraints
+* Links are not allowed as constraints
+* Constraints cannot have extras
+
How to test
-----------
@@ -1089,6 +1095,7 @@ How to test
- installing several packages simultaneously
- re-creating an environment using a ``requirements.txt`` file
- using ``pip --force-reinstall`` to check whether it does what you think it should
+ - using constraints files
- If you have a build pipeline that depends on pip installing your
dependencies for you, check that the new resolver does what you
need.