--- a/mercurial/help/internals/bundles.txt	Mon Feb 26 23:54:40 2018 +0530
+++ b/mercurial/help/internals/bundles.txt	Sat Feb 17 11:19:52 2018 -0700
@@ -63,8 +63,7 @@
 
 ``HG20`` is currently the only defined bundle2 version.
 
-The ``HG20`` format is not yet documented here. See the inline comments
-in ``mercurial/exchange.py`` for now.
+The ``HG20`` format is documented at :hg:`help internals.bundle2`.
 
 Initial ``HG20`` support was added in Mercurial 3.0 (released May
 2014). However, bundle2 bundles were hidden behind an experimental flag