Clarify what ":errorhandler" refers to.
diff --git a/Doc/using/cmdline.rst b/Doc/using/cmdline.rst
index 7d9ecad..94fbed7 100644
--- a/Doc/using/cmdline.rst
+++ b/Doc/using/cmdline.rst
@@ -484,7 +484,8 @@
.. envvar:: PYTHONIOENCODING
Overrides the encoding used for stdin/stdout/stderr, in the syntax
- encodingname:errorhandler, with the :errors part being optional.
+ ``encodingname:errorhandler``. The ``:errorhandler`` part is optional and
+ has the same meaning as in :func:`str.encode`.
.. versionadded:: 2.6