Specify what kind of warning -3 emits.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 8039795..d3120b5 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -326,6 +326,8 @@
    * :func:`reduce`
    * :func:`reload`
 
+   Using these will emit a :exc:`DeprecationWarning`.
+
    .. versionadded:: 2.6