diff --git a/doc/formats.texi b/doc/formats.texi
index aac80ff9c0..bdae84232e 100644
--- a/doc/formats.texi
+++ b/doc/formats.texi
@@ -55,6 +55,8 @@ Do not merge side data.
 Enable RTP MP4A-LATM payload.
 @item nobuffer
 Reduce the latency introduced by optional buffering
+@item bitexact
+Only write binary portable, build and time independant data.
 @end table
 
 @item seek2any @var{integer} (@emph{input})