The Serialized Form page for Tiger contains mention of a bunch of anonymous classes that don't belong there.  For example, go to this anchor on the page:

http://webmirror.sfbay/j2se/1.5.0/docs/api/serialized-form.html#java.util.ArrayList

and page up, and there are these anonymous classes:

- Class java.util.AbstractMap$1 extends Object implements Serializable
- Class java.util.AbstractMap$1$1 extends Object implements Serializable
- Class java.util.AbstractMap$2 extends Object implements Serializable
- Class java.util.AbstractMap$2$1 extends Object implements Serializable

These classes are non-public, do not have "@serial include" (how could they?), and they don't even implement Serializable.  (And FWIW, AbstractMap$1 actually extends AbstractSet, and AbstractMap$2 actually extends AbstractCollection.)

There is a similar batch under java.util.Collections, after its correctly @serial-included nested member classes, and a few more under SubList, TreeMap, and Vector; for whatever reason, there do not appear to be any examples that are unrelated to collections classes.

Compare with the 1.4.2 page:

http://webmirror.sfbay/j2se/1.4.2/docs/api/serialized-form.html#java.util.ArrayList

This bug appears closely related to 4923163, which was marked fixed in Tiger Beta, but seems to have been re-exposed for Beta2 when 4982231 was integrated.