File 3531-Reference-manual-Improve-documentation-of-the-refere.patch of Package erlang

From 22cc3a7ed0f3cd2e35912acd9ac6242d6296876a Mon Sep 17 00:00:00 2001
From: Rickard Green <rickard@erlang.org>
Date: Tue, 23 Mar 2021 22:59:34 +0100
Subject: [PATCH 1/6] Reference manual: Improve documentation of the
 'reference' type

0123456789012345678901234567890123456789012345678901234567890123456789
---
 system/doc/reference_manual/data_types.xml | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/system/doc/reference_manual/data_types.xml b/system/doc/reference_manual/data_types.xml
index 4904d92e09..9405dca0a1 100644
--- a/system/doc/reference_manual/data_types.xml
+++ b/system/doc/reference_manual/data_types.xml
@@ -163,8 +163,15 @@ phone_number
 
   <section>
     <title>Reference</title>
-    <p>A reference is a term that is unique in an Erlang runtime
-      system, created by calling <c>make_ref/0</c>.</p>
+    <p>
+      A term that is
+      <seealso marker="system/efficiency_guide:advanced#unique_references">unique</seealso>
+      among connected nodes. A reference can be created by calling the
+      <seealso marker="erts:erlang#make_ref/0"><c>make_ref/0</c></seealso>
+      BIF. The
+      <seealso marker="erts:erlang#is_reference/1"><c>is_reference/1</c></seealso>
+      BIF can be used to test if a term is a reference.
+    </p>
   </section>
 
   <section>
-- 
2.26.2