spv-file-format: Footnotes can't refer to footnotes.

diff --git a/doc/dev/spv-file-format.texi b/doc/dev/spv-file-format.texi
index 0e3eb19e88658cf396c726c41c6633a6ca2ddd55..49662dd7acc267af24dc27ca2af4a0d53fe4e3db 100644 (file)
--- a/doc/dev/spv-file-format.texi
+++ b/doc/dev/spv-file-format.texi
@@ -1067,6 +1067,9 @@ Footnote => Value[text] (58 @math{|} 31 Value[marker]) int32[show]
 Each footnote has @code{text} and an optional custom @code{marker}
 (such as @samp{*}).
 
+The syntax for Value would allow footnotes (and their markers) to
+reference other footnotes, but in practice this doesn't work.
+
 @code{show} is a 32-bit signed integer.  It is positive to show the
 footnote or negative to hide it.  Its magnitude is often 1, and in
 other cases tends to be the number of references to the footnote.