diff --git a/src/documentation/content/xdocs/hpbf/file-format.xml b/src/documentation/content/xdocs/hpbf/file-format.xml
index 088ecf651..591204951 100644
--- a/src/documentation/content/xdocs/hpbf/file-format.xml
+++ b/src/documentation/content/xdocs/hpbf/file-format.xml
@@ -90,6 +90,79 @@ Root Entry -
At 0x200 we have the text, stored as little endian 16 bit unicode.
After the text comes all sorts of other stuff, presumably as
described by the sequences.
+ For a contents stream of length 7168 / 0x1c00 bytes, the start
+ looks something like:
+