Wendy McElroy, a theorist and activist concerned with individualist feminism as opposed to classist "gender feminism," cites the great Austrian economist Ludwig von Mises in making a distinction between caste and class. A class is an arbitrary conceptual grouping, while a caste is a set of people enjoying special legal privileges, and often legal barriers to entry into the group. If there are legal statutes or policemen preventing the exercise of rights for some group, such as the right to contract, hold property, or engage in certain activities or occupations, then one may properly speak of a caste. If there are no such legal barriers, then speaking of "class interests" generally has little or no basis or coherant meaning.
In The Free and Prosperous Commonwealth, Mises defined a status society as one "constituted not of citizens with equal rights, but divided into ranks vest with different duties and prerogatives..."
It was under a caste system, not a class one, that necessary conflicts arose between legal categories of people who were accorded different privileges and disabilities. Thus, the phrase 'class warfare' is a mistaken one: it should be 'caste warfare'. Moreover, so-called 'class warfare' contains further confusion. For example, the phrase usually assumes that there is an "identity of interests among the members of the separate classes." Yet, as Mises explained in The Free and Prosperous Commonwealth, a common identity does not necessarily mean a common interests since individual members of a class will tend to give their own individual interests priority. Ironically, this may well lead to competition among 'class' members, rather than commonality. - Wendy McElroy, Mises' Legacy to Feminism