`@serial` is a doc comment tag that should be used on serializable fields of serializable objects, or on classes or packages to control the documentation.

In no case is it applicable to any methods on serializable objects.

The following instances have been observed in JDK documentation comments.

open/src/java.desktop/share/classes/java/applet/Applet.java:111: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/Button.java:487: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/Checkbox.java:663: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/CheckboxMenuItem.java:478: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/Choice.java:711: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/Container.java:3726: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/Font.java:1944: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/Label.java:169: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/MenuComponent.java:450: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/event/FocusEvent.java:389: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/event/KeyEvent.java:2009: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.desktop/share/classes/java/awt/event/MouseEvent.java:1197: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
     * @serial
open/src/java.base/share/classes/java/security/Provider.java:866: warning: Tag @serial cannot be used in method documentation. It can only be used in the following types of documentation: package, class/interface, field.
    * @serial