1) Comparator:

   "A class's natural ordering is said to be consistent with equals if
  and only if (e1.compareTo((Object)e2)==0) has the same boolean value
  as e1.equals((Object)e2) for every e1 and e2 of class C."

  This part of the spec should be clarified as follows:

  A class's natural ordering is said to be consistent with equals if
  and only if (e1.compareTo((Object)e2)==0) has the same boolean value
  as e1.equals((Object)e2) for every e1 and e2 of class C for which the
  former expression is defined (i.e., does not thrown an exception).

2) Comparator:

    For example, if one adds two keys a and b such that
    (a.equals((Object)b) && c.compare((Object)a, (Object)b) != 0)
    to a sorted set with comparator c, the second add operation
    will return false (and the size of the sorted set will not
    increase) because a and b are equivalent from the sorted
    set's perspective.
    
Typo. Should be:

    (!a.equals((Object)b) && c.compare((Object)a, (Object)b) == 0)

3) Map: It would be convenient for Map.entrySet to @see Map.Entry.