From 1facc7dc3a2ee1b4b9172fe8f2b48a7453e27edc Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Wed, 12 May 2021 18:07:29 -0700
Subject: [PROPOSED] Mention ustar compatibility issue

* tz-link.html: Mention that releases before 1999g might not be
ustar-compatible.  (Thanks to Peter Adelman for reporting the
problem.)
---
 tz-link.html | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tz-link.html b/tz-link.html
index 073cd31..a240277 100644
--- a/tz-link.html
+++ b/tz-link.html
@@ -167,6 +167,10 @@ Since 1996, each version has been a four-digit year followed by
 lower-case letter (<samp>a</samp> through <samp>z</samp>,
 then <samp>za</samp> through <samp>zz</samp>, then <samp>zza</samp>
 through <samp>zzz</samp>, and so on).
+Since version 1999g, each release has been distributed in
+<a href="https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06">POSIX
+ustar interchange format</a>, compressed as described above;
+older releases use a nearly-compatible format.
 Since version 2016h, each release has contained a text file named
 "<samp>version</samp>" whose first (and currently only) line is the version.
 Older releases are <a href="https://ftp.iana.org/tz/releases/">archived</a>,
-- 
2.27.0