diff --git a/xstream-distribution/src/content/changes.html b/xstream-distribution/src/content/changes.html
index 7df8a69ff..0aecff5bf 100644
--- a/xstream-distribution/src/content/changes.html
+++ b/xstream-distribution/src/content/changes.html
@@ -117,6 +117,13 @@ <h2>Minor changes</h2>
 		<li>GHI:#342: Optimize internal handling of children in DomReader avoiding O(n²) access times for siblings (by Shiang-Yun Yang).</li>
 	</ul>
 
+	<h2>API changes</h2>
+
+	<ul>
+		<li>Added constant c.t.x.io.xml.PrettyPrintWriter.XML_1_0_REPLACEMENT.</li>
+		<li>Added constant c.t.x.io.xml.PrettyPrintWriter.XML_1_1_REPLACEMENT.</li>
+	</ul>
+
 	<h1 id="1.4.20">1.4.20</h1>
 
 	<p>Released December 24, 2022.</p>
diff --git a/xstream/src/java/com/thoughtworks/xstream/io/xml/PrettyPrintWriter.java b/xstream/src/java/com/thoughtworks/xstream/io/xml/PrettyPrintWriter.java
index aa7ef98c8..ed09761c3 100644
--- a/xstream/src/java/com/thoughtworks/xstream/io/xml/PrettyPrintWriter.java
+++ b/xstream/src/java/com/thoughtworks/xstream/io/xml/PrettyPrintWriter.java
@@ -51,10 +51,31 @@
  */
 public class PrettyPrintWriter extends AbstractXmlWriter {
 
+    /** Quirks mode: Writes any character into data stream incl. U+0000. */
     public static int XML_QUIRKS = -1;
+    /**
+     * XML 1.0 mode: Writes characters according XML 1.0 specification, throws {@link StreamException} for invalid
+     * characters.
+     */
     public static int XML_1_0 = 0;
+    /**
+     * XML 1.1 mode: Writes characters according XML 1.1 specification, throws {@link StreamException} for invalid
+     * characters.
+     */
     public static int XML_1_1 = 1;
+    /**
+     * XML 1.0 mode: Writes characters according XML 1.0 specification, writes character U+FFFFD as replacement for
+     * invalid ones.
+     *
+     * @since upcoming
+     */
     public static int XML_1_0_REPLACEMENT = 2;
+    /**
+     * XML 1.1 mode: Writes characters according XML 1.1 specification, writes character U+FFFFD as replacement for
+     * invalid ones.
+     *
+     * @since upcoming
+     */
     public static int XML_1_1_REPLACEMENT = 3;
 
     private final QuickWriter writer;