--- a/mercurial/help/internals/wireprotocol.txt	Fri Apr 13 12:31:34 2018 -0700
+++ b/mercurial/help/internals/wireprotocol.txt	Fri Apr 13 12:31:56 2018 -0700
@@ -1770,6 +1770,10 @@
       name
          Name of the compression engine. e.g. ``zstd`` or ``zlib``.
 
+framingmediatypes
+   An array of bytestrings defining the supported framing protocol
+   media types. Servers will not accept media types not in this list.
+
 heads
 -----