I am new to the game (I received the Advanced Fantasy Referee's & Player's Tome in a Humble Bundle a while back), so I may not be as knowledgeable about the terminology as someone more experienced (like yourself).

In the Advanced Fantasy Player's Tome, page 14 lists two different ways to generate characters - Basic & Advanced. I would like to play with the Demihumans as Character Classes, so that would be the Basic Character Creation system, which specifies all characters are human unless they select a demihuman class.

I know that can feel a little restrictive but I have always been fascinated by the idea of racial classes and would love to give it a try.

The book does say the two systems are compatible, so I guess it does not super matter. I am just entertained by the idea of someone playing a demihuman as a class.