diff --git a/required/tools/changes.txt b/required/tools/changes.txt
index d5a605a66..109de4c76 100644
--- a/required/tools/changes.txt
+++ b/required/tools/changes.txt
@@ -5,6 +5,11 @@ completeness or accuracy and it contains some references to files that
 are not part of the distribution.
 =======================================================================
 
+2024-12-22  David Carlisle  <David.Carlisle@latex-project.org>
+
+	* xr.dtx: additional documentation of problems with
+          incompatible citation packages (gh/1588)
+
 2024-11-12  Frank Mittelbach  <Frank.Mittelbach@latex-project.org>
 	* multicol.dtx (subsection{Tagging support}):
 	Added another socket to support tagging.
diff --git a/required/tools/xr.dtx b/required/tools/xr.dtx
index daa0778b3..f1f6ac714 100644
--- a/required/tools/xr.dtx
+++ b/required/tools/xr.dtx
@@ -25,9 +25,9 @@
 %
 %<package>\NeedsTeXFormat{LaTeX2e}
 %<package>\DeclareRelease{v5}{2023-07-04}{xr-2023-07-04.sty}
-%<package>\DeclareCurrentRelease{}{2024-04-10}
+%<package>\DeclareCurrentRelease{}{2024-12-22}
 %<package>\ProvidesPackage{xr}
-%<package>         [2024-04-10 v6.00 eXternal References (DPC)]
+%<package>         [2024-12-22 v6.00 eXternal References (DPC)]
 %
 %<*driver>
 \documentclass{l3doc}
@@ -156,7 +156,13 @@ Bug reports can be opened (category \texttt{#1}) at\\%
 % \meta{prefix}:
 % \begin{verbatim}
 %  \externaldocument[][nocite]{aaa}
-% \end{verbatim}  
+% \end{verbatim}
+%
+% Problems with citing references from an external document
+% are more likely if the documents are using different citation packages.
+% So if possible, it is best to ensure that the documents use compatible
+% packages so that the citation data works without error when imported from
+% the external document.
 % 
 % The `document' referred to by the main argument \meta{document} is the file
 % \file{document.aux} which must be somewhere on TeX's input path.