From f0178deecbb56283fda8f4c504c8fe16ce23e1a6 Mon Sep 17 00:00:00 2001
From: Daniel Gustafsson <dgustafsson@postgresql.org>
Date: Thu, 6 Aug 2026 14:07:57 +0200
Subject: [PATCH] doc: Define MXID as an acronym

XID is defined as an acronym in the documentation but MXID (Multixact
ID) was missing from the acronym list.  This adds MXID as an acronym
and links it to the "Multixacts and Wraparound" section.

Author: Koshino Taiki <koshino@sraoss.co.jp>
Discussion: https://postgr.es/m/OS9PR01MB17364A940ACFCADBB7593498A94D32@OS9PR01MB17364.jpnprd01.prod.outlook.com
---
 doc/src/sgml/acronyms.sgml    | 9 +++++++++
 doc/src/sgml/maintenance.sgml | 3 ++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/doc/src/sgml/acronyms.sgml b/doc/src/sgml/acronyms.sgml
index 2f906e9f018..4dc3eaf3cef 100644
--- a/doc/src/sgml/acronyms.sgml
+++ b/doc/src/sgml/acronyms.sgml
@@ -494,6 +494,15 @@
     </listitem>
    </varlistentry>
 
+   <varlistentry>
+    <term><acronym>MXID</acronym></term>
+    <listitem>
+     <para>
+      <link linkend="vacuum-for-multixact-wraparound">Multixact Identifier</link>
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term><acronym>NLS</acronym></term>
     <listitem>
diff --git a/doc/src/sgml/maintenance.sgml b/doc/src/sgml/maintenance.sgml
index e351e5e9ca1..33ab4edf87c 100644
--- a/doc/src/sgml/maintenance.sgml
+++ b/doc/src/sgml/maintenance.sgml
@@ -766,7 +766,8 @@ HINT:  Execute a database-wide VACUUM in that database.
     </indexterm>
 
     <para>
-     <firstterm>Multixact IDs</firstterm> are used to support row locking by
+     <firstterm>Multixact IDs</firstterm> (<acronym>MXID</acronym>)
+     are used to support row locking by
      multiple transactions.  Since there is only limited space in a tuple
      header to store lock information, that information is encoded as
      a <quote>multiple transaction ID</quote>, or multixact ID for short,