numerous tidy warnings "<a> cannot copy name attribute to id".
see, e.g., javax/swing/package-use.html:

line 647 column 20 - Warning: <a> cannot copy name attribute to id
line 1140 column 20 - Warning: <a> cannot copy name attribute to id
line 1398 column 20 - Warning: <a> cannot copy name attribute to id
line 1735 column 20 - Warning: <a> cannot copy name attribute to id
line 2172 column 20 - Warning: <a> cannot copy name attribute to id

line 647:
<div class="block"><a name="../../javax/swing/jtree_description"></a>

line 1140:
<div class="block"><a name="../../javax/swing/jtree_description"></a>

the same for javax/swing/class-use/Scrollable.html, java/awt/image/class-use/ImageObserver.html, etc.

the hyperlink is defined in javax/swing/JTree.java: <a name="jtree_description"></a>