From b8e8032e6d1f4ece3342cf4c0f547cc59cd7fd13 Mon Sep 17 00:00:00 2001
From: Timo Stamm <ts@timostamm.de>
Date: Wed, 23 Sep 2026 19:22:33 +0200
Subject: [PATCH] Clarify that bytes.uuid checks length only

---
 proto/protovalidate/buf/validate/validate.proto | 10 ++++++----
 tools/internal/gen/buf/validate/validate.pb.go  | 10 ++++++----
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/proto/protovalidate/buf/validate/validate.proto b/proto/protovalidate/buf/validate/validate.proto
index 0ad730c4..f7ef4383 100644
--- a/proto/protovalidate/buf/validate/validate.proto
+++ b/proto/protovalidate/buf/validate/validate.proto
@@ -4124,10 +4124,12 @@ message BytesRules {
       }
     ];
 
-    // `uuid` ensures that the field value encodes 128-bit UUID data as defined
-    // by [RFC 4122](https://datatracker.ietf.org/doc/html/rfc4122#section-4.1.2).
-    // The field must contain exactly 16 bytes representing the UUID. If the
-    // field value isn't a valid UUID, an error message will be generated.
+    // `uuid` ensures that the field `value` is exactly 16 bytes long,
+    // the size of a UUID in binary form as defined by
+    // [RFC 9562](https://datatracker.ietf.org/doc/html/rfc9562#section-4).
+    // Only the length is enforced: the version and variant fields
+    // are not checked, and any 16 bytes are accepted.
+    // If the field value doesn't meet this rule, an error message is generated.
     //
     // ```proto
     // message MyBytes {
diff --git a/tools/internal/gen/buf/validate/validate.pb.go b/tools/internal/gen/buf/validate/validate.pb.go
index 33d85c00..e4de90ce 100644
--- a/tools/internal/gen/buf/validate/validate.pb.go
+++ b/tools/internal/gen/buf/validate/validate.pb.go
@@ -6063,10 +6063,12 @@ type BytesRules_Ipv6 struct {
 }
 
 type BytesRules_Uuid struct {
-	// `uuid` ensures that the field value encodes 128-bit UUID data as defined
-	// by [RFC 4122](https://datatracker.ietf.org/doc/html/rfc4122#section-4.1.2).
-	// The field must contain exactly 16 bytes representing the UUID. If the
-	// field value isn't a valid UUID, an error message will be generated.
+	// `uuid` ensures that the field `value` is exactly 16 bytes long,
+	// the size of a UUID in binary form as defined by
+	// [RFC 9562](https://datatracker.ietf.org/doc/html/rfc9562#section-4).
+	// Only the length is enforced: the version and variant fields
+	// are not checked, and any 16 bytes are accepted.
+	// If the field value doesn't meet this rule, an error message is generated.
 	//
 	// ```proto
 	//