From a432709ef2943c2d96f249649f9d2057cd8c9550 Mon Sep 17 00:00:00 2001
From: mejrs <59372212+mejrs@users.noreply.github.com>
Date: Mon, 13 Apr 2026 23:37:37 +0200
Subject: [PATCH] Document diagostic attribute duplicates

---
 src/attributes/diagnostics.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/attributes/diagnostics.md b/src/attributes/diagnostics.md
index d1d1b65ddc..6d27dc24e0 100644
--- a/src/attributes/diagnostics.md
+++ b/src/attributes/diagnostics.md
@@ -575,6 +575,9 @@ The `note` option can appear several times, which results in several note messag
 r[attributes.diagnostic.on_unimplemented.repetition]
 If any of the other options appears several times the first occurrence of the relevant option specifies the actually used value. Subsequent occurrences generates a warning.
 
+r[attributes.diagnostic.on_unimplemented.duplicates]
+The `diagnostic::on_unimplemented` attribute may be used any number of times. All keys from all uses of the attribute will be used and are subject to the repetition rules.
+
 r[attributes.diagnostic.on_unimplemented.unknown-keys]
 A warning is generated for any unknown keys.