I try to explain how I think of them in terms of behaviors and motivations for behavior, and how to identify them, but then people keep saying I'm being too general and saying it could just as easily be something else, not everyone is like that, yada yada yada.
If you can't categorize things according to letters and CF's, then what's the point? There is no system apart from that, and it doesn't in any way translate into anything outside of your head if you can't make generalizations which are observable. Either people of a certain type behave a certain way or they don't, and in the latter case, the system is worthless. And as far as processing information goes, there has to be some way of knowing how someone processes information.
Yes, JCF is not behavior or persona. This comes in with theories like Keirsey, and I know very early on a couple of Sensors agreed that my persona seemed ESFP...one ISTP and one ISTJ kept insisting this, and after being close to an ISxJ for several years, he decided that ISFP was actually the best fit for me, as the "extroversion" seemed to be a kind of persona.
Also on the Keirsey site they looked at my video and said I seemed ESFP.
However, here, a couple of people still suggested ISFP for me after seeing my video.
I think "in person" the most common typings for me were ENFP, ESxP, and ENFj.
It really depends on which theory you follow, honestly.
It also depends on how accurately and completely you're seeing the "subject" at hand, which is impossible to do from casual forum contact in many cases, except for glaring repeated examples of something over and over again.
Jung took years to "type" his patients, typically.
People will essentially say "x" or "y" person is typed correctly if it agrees most with the theory they themselves prefer.
One of the reasons I recently put "SEE" as my type was so that people could comprehend that I specifically mean the Socionics theory, the relatively asocial, small-group-preferring ESFp in Socionics is not the wildly social ESFP party animal that some other people think of.
I still think it's most likely that in JCF I'm probably an ISFP. Fi seems to be my preferred function, and I use too much Ni to be an Se dom, but I also use too much sensing to be an ENFP, and the type of sensing I use actually has more to do with Jungian's definition of the Se type than the Si type, anyway.
I think being an Se/Fi or Fi/Se type is probably why I bug an unnatural number of self-typed INTJs on the Internet. "Oh irrational, oh bold and uncontrollable monstrous ho-bag of a woman, shut your fool mouth" is pretty much what a lot of them seem to project on me.
It's kind of entertaining, to be perfectly honest with you, but I'm tired of "getting into trouble."
Especially since they are so unlikely their own bias and irrationality as a type, for whatever reason.