A DESCRIPTION OF THE PROBLEM :
The link to Collections Framework Tutorial on the bottom of the page is borken. Why not change it to
http://java.sun.com/docs/books/tutorial/collections/
where it really is (i.e. drop the "www." part).

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
http://java.sun.com/docs/books/tutorial/collections/
ACTUAL -
http://www.java.sun.com/docs/books/tutorial/collections/

URL OF FAULTY DOCUMENTATION :
http://java.sun.com/javase/6/docs/api/java/util/package-summary.html