Add cautionary note on the use of PySequence_Fast_ITEMS.
diff --git a/Doc/c-api/sequence.rst b/Doc/c-api/sequence.rst
index 359bf6d..e16c2e3 100644
--- a/Doc/c-api/sequence.rst
+++ b/Doc/c-api/sequence.rst
@@ -143,6 +143,10 @@
Return the underlying array of PyObject pointers. Assumes that *o* was returned
by :cfunc:`PySequence_Fast` and *o* is not *NULL*.
+
+ Note, if a list gets resized, the reallocation may relocate the items array.
+ So, only use the underlying array pointer in contexts where the sequence
+ cannot change.
.. versionadded:: 2.4