[tz] [PATCH 1/3] * backward: Add backward-compatibility comment.

[Paul Eggert]

---
 backward | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/backward b/backward
index a8fd620..5a86400 100644
--- a/backward
+++ b/backward
@@ -8,6 +8,10 @@
 # also present in the file 'backzone', which has data important only
 # for pre-1970 timestamps and so is out of scope for tzdb proper.
 
+# Although this file is optional and tzdb will work if you omit it by
+# building with 'make BACKWARD=', in practice downstream users
+# typically use this file for backward compatibility.
+
 # Link	TARGET			LINK-NAME
 Link	Africa/Nairobi		Africa/Asmera
 Link	Africa/Abidjan		Africa/Timbuktu
-- 
2.36.1