<p> This class defines a <code>compareTo(...)</code> method but inherits its
  <code>equals()</code> method from <code>java.lang.Object</code>.
  Generally, the value of compareTo should return zero if and only if
  equals returns true. If this is violated, weird and unpredictable
  failures will occur in classes such as PriorityQueue.
  In Java 5 the PriorityQueue.remove method uses the compareTo method,
  while in Java 6 it uses the equals method.

<p>From the JavaDoc for the compareTo method in the Comparable interface:
<blockquote>
It is strongly recommended, but not strictly required that <code>(x.compareTo(y)==0) == (x.equals(y))</code>.
Generally speaking, any class that implements the Comparable interface and violates this condition
should clearly indicate this fact. The recommended language
is "Note: this class has a natural ordering that is inconsistent with equals."
</blockquote>

<p>
This rule is deprecated, use {rule:squid:S1210} instead.
</p>