The serialized-form page in the JDK API has hundreds of broken links.

A large number of these are caused because the serialized-form page contains info about private fields if they are part of the serial form, and (not unreasonably), the doc comments for these private members may contain references (i.e. @see, {@link}) to other private members, which may not themselves be documented. The bottom line is that references should not be linked if the target of that link will not be available.