This site provides a good description of Harry Benjamin Syndrome. Dr. Benjamin pioneered allot of the research into this condition. Harry Benjamin Syndrome (HBS) is a current classification of what is generally referred to as GID (Gender Identity Disorder). HBS removes the stigma of it being a psychological issue, to that of a physiological one, akin to any other birth defect.
Here is the actual text from the DSM-IV manual that psychologists use for classifying a diagnosis. This is what they're compelled to follow when working with someone who feels they need to correct their gender.
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