Issue #14954: Clarify the interaction of weak references and garbage collection.
Patch by Ethan Furman.
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
index 2ad1e56..224f442 100644
--- a/Doc/library/weakref.rst
+++ b/Doc/library/weakref.rst
@@ -24,7 +24,10 @@
A weak reference to an object is not enough to keep the object alive: when the
only remaining references to a referent are weak references,
:term:`garbage collection` is free to destroy the referent and reuse its memory
-for something else. A primary use for weak references is to implement caches or
+for something else. However, until the object is actually destroyed the weak
+reference may return the object even if there are no strong references to it.
+
+A primary use for weak references is to implement caches or
mappings holding large objects, where it's desired that a large object not be
kept alive solely because it appears in a cache or mapping.