The following issues are reported regarding headings in documentation comments.
For a general background information, see this message to jdk-dev@ojn.
   https://mail.openjdk.java.net/pipermail/jdk-dev/2019-March/002671.html



open/src/java.desktop/share/classes/java/awt/font/TextAttribute.java:70: Note: missing heading <h2>
 * <H3>Values</H3>
   ^
open/src/java.desktop/share/classes/java/awt/Font.java:77: Note: missing heading <h2>
 * <h3>Characters and Glyphs</h3>
   ^
open/src/java.desktop/share/classes/java/awt/AlphaComposite.java:166: Note: missing heading <h2>
 * <h3>Preparing Inputs</h3>
   ^
open/src/java.desktop/share/classes/java/awt/Component.java:138: Note: missing heading <h2>
 * <h3>Serialization</h3>
   ^
open/src/java.desktop/share/classes/java/awt/geom/AffineTransform.java:49: Note: missing heading <h2>
 * <h3><a id="quadrantapproximation">Handling 90-Degree Rotations</a></h3>
   ^
open/src/java.desktop/share/classes/javax/swing/SizeSequence.java:79: Note: missing heading <h2>
 * <h3>Implementation Notes</h3>
   ^
open/src/java.desktop/share/classes/javax/swing/Action.java:72: Note: missing heading <h2>
 * <h3><a id="buttonActions"></a>Swing Components Supporting <code>Action</code></h3>
   ^
open/src/java.desktop/share/classes/javax/swing/UIManager.java:73: Note: missing heading <h2>
 * <h3>Specifying the look and feel</h3>
   ^
open/src/java.desktop/share/classes/javax/swing/plaf/metal/DefaultMetalTheme.java:45: Note: missing heading <h2>
 * <h3><a id="fontStyle"></a>Font Style</h3>
   ^
open/src/java.desktop/share/classes/javax/swing/GroupLayout.java:2380: Note: missing heading <h2>
     * <h3>Baseline</h3>
       ^
open/src/java.desktop/share/classes/javax/swing/SpringLayout.java:131: Note: missing heading <h2>
 * <h3>
   ^
open/src/java.desktop/share/classes/javax/swing/JTable.java:3053: Note: low heading <h3>
     * <H3> Distributing the delta </H3>
       ^
open/src/java.desktop/share/classes/javax/print/DocFlavor.java:63: Note: missing heading <h2>
 * <h3>Client Formatted Print Data</h3>
   ^
open/src/java.desktop/share/classes/javax/print/package-info.java:37: Note: missing heading <h2>
 * <h3>Print Service Discovery</h3>
   ^
open/src/java.desktop/share/classes/javax/print/attribute/standard/package-info.java:85: Note: missing heading <h2>
 * <h3>Attribute Organization</h3>
   ^
open/src/java.desktop/share/classes/javax/print/attribute/package-info.java:30: Note: missing heading <h2>
 * <h3>What is an Attribute?</h3>
   ^
open/src/java.desktop/share/classes/javax/accessibility/package-info.java:40: Note: missing heading <h2>
 * <h3><a id="Accessible"></a><a href="Accessible.html">Interface
   ^