Most of the definitions and explanations here appear to me to be "external" ones - i.e. how to talk about others.

It always seemed to me that the definition of a "class" had to be an "internal" one. You don't know, and aren't supposed to know, who is a member of "the class" unless you are a member. And those who really are may be polite enough to let you think you are - but they all know better.

Economic standing, education, and all the other obvious "criteria" are accurate enough for categorizing and (dis)cussing people as groups, but aren't really very helpful in understanding a "class system" as originally posited for discussion.

But of course I have no class so I may be mistaken ...

John