Ratings. Yes & No.
In most of Southern Africa you have to get a rating on EACH aircraft type.
So for example the move from C150 to C172 to C206 to C210 requires a written tech exam AND a couple of hours flying conversion by an instructor. This even applies with the move from C210 to C210 turbo. These exams/conversion flights are not arduous and can be done in a day, but be prepared.
I am not absolutely sure about this but I think if you have a British CPL with a C210 in your log bok endorsed by an instructor, then they accept this as a rating. I will have to check this with Zambian CAA