What is Classification?

Legal Definition
Classification is a general process related to categorization, the process in which ideas and objects are recognized, differentiated, and understood.

A classification system is an approach to accomplishing classification.
-- Wikipedia
Legal Definition
In the practice of the English chancery division, where there are several parties to an administration action, including those who have been served with notice of the decree or judgment, and it appears to the judge (or chief clerk) that any of them form a class having the same interest, (e. g., residuary legatees,) he may require them to be represented by one solicitor, in order to prevent the expense of each of them attending by separate solicitors. This is termed "classlfying the interests of the parties attending," or, shortly, "classifying," or "classification." In practice the term is also applied to the directions given by the chief clerk as to which of the parties are to attend on each of the accounts and inquiries directed by the judgment. Sweet
-- Black's Law Dictionary
Legal Definition
The English chancery practice of assigning litigants having similar interests in the cause to one solicitor, to save expense.
-- Ballentine's Law Dictionary