Since I research categories #3, #4, and #5 (many of whom claim #2), I agree with you that it is important to understand the "definitions" of the terms, if only so you know what type of records to reseach, where and when they were generated.

However, as far as I can see the only strict adherence to the caste system that you described is how it is to the advantage of #1 at any given time, place and space.

I can assure you when I research folks, I research everyone, especially the folks who are making the laws (category#1), generating the records and who have "control" of the record.

Definitions are fine, the question is how they were applied in real time at the time and to whose advantage..

Selma

Reason:
During that time in our American history, this country, "from sea to shining sea", had a very strong caste system and a hierarchy:
1)Whites,
2)Indians,
3)"Free People of Color"
4)"Emancipated ("Freed") People of Color".
5)"Slaves".

To NOT differentiate between the two castes (#3 and #4) would make this entire discussion MEANINGLESS!