From 01c97ab8b6161dbb567353f10b822125befce6ca Mon Sep 17 00:00:00 2001
From: elasota <1137273+elasota@users.noreply.github.com>
Date: Fri, 22 Mar 2024 19:17:50 -0400
Subject: [PATCH] Clarify value-limiting behavior for offset codes (since they
 have no upper bound)

---
 doc/zstd_compression_format.md | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/doc/zstd_compression_format.md b/doc/zstd_compression_format.md
index b2653f8d784..538cb6256e9 100644
--- a/doc/zstd_compression_format.md
+++ b/doc/zstd_compression_format.md
@@ -1125,8 +1125,14 @@ the last byte used or partially used by probability decoding.  If the last
 byte was partially used, then any unused bits are ignored.
 
 If this process results in a non-zero probability for a value outside of the
-valid range of values that the FSE table is defined for, even if that value is
-not used, then the data is considered corrupted.
+valid range of values that the FSE table is defined for, then the data is
+considered corrupted, even if the value is not used.
+
+In the case of offset codes, a decoder may reject a frame that encodes a
+non-zero probability for an offset code that exceeds the decoder's
+maximum allowed offset code.  A compliant encoder should not emit non-zero
+probabilities for offset codes that are greater than the highest offset
+code value present in the data stream.
 
 __Example__ :