diff --git a/pep-0454.txt b/pep-0454.txt
index 2334b7b8b..8d2beca29 100644
--- a/pep-0454.txt
+++ b/pep-0454.txt
@@ -88,6 +88,23 @@ implementations of Python may not be able to provide it.
 API
 ===
 
+To trace most memory blocks allocated by Python, the module should be
+enabled as early as possible by setting the ``PYTHONTRACEMALLOC``
+environment variable to ``1``, or by using ``-X tracemalloc`` command
+line option. The ``tracemalloc.enable()`` function can be called at
+runtime to start tracing Python memory allocations.
+
+By default, a trace of an allocated memory block only stores the most
+recent frame (1 frame). To store 25 frames at startup: set the
+``PYTHONTRACEMALLOC`` environment variable to ``25``, or use the ``-X
+tracemalloc=25`` command line option. The ``set_traceback_limit()``
+function can be used at runtime to set the limit.
+
+By default, Python memory blocks allocated in the ``tracemalloc`` module
+are ignored using a filter. Use ``clear_filters()`` to trace also these
+memory allocations.
+
+
 Main Functions
 --------------