This is pure brilliance. The depth of reasearch they went to for some of the units is mind-boggling

--- start quote ---

    /*  From Department of the Army's authoritative study: "Effects of
        Nuclear Weapons", footnote 3 to section 1.45, available at:
        http://www.fourmilab.ch/etexts/www/effects/

       "The majority of the experimental and theoretical values of the
       explosive energy released by TNT range from 900 to 1,100 calories per
       gram.  At one time, there was some uncertainty as to whether the term
       "kiloton" of TNT referred to a short kiloton (2 x 10^6 pounds), a
       metric kiloton (2.205 x 10^6 pounds), or a long kiloton (2.24 x 10^6
       pounds).  In order to avoid ambiguity, it was agreed that the term
       "kiloton" would refer to the release of 10^12 calories of explosive
       energy.  This is equivalent to 1 short kiloton of TNT if the energy
       release is 1,102 calories per gram or to 1 long kiloton if the energy
       is 984 calories per gram of TNT."

       So, evidently they don't quite specify which ton is required...

--- end quote ---

And it goes on