The second part of the classification is the exponent, which helps represent a total threat level, and takes into consideration skills and resources, as well as powers that are not part of someone's genetic potential. Exponents are assigned if, for some reason, the mutant/human in question poses either more or less of a threat through training, skills, injury, et cetera.

Note that an exponent can be less than the base, for example, in the case of Cable. Also note that the exponenet is the rating which limits you. You can have four characters all with the same base, as long as the exponents meet the restrictions given under each rating.

Finally, if a rating does not have an exponent, the exponent is assumed to be the same as the base.