graceljh,
You may get what you are happy with in 2009 Standard about actual mating envelope. They give comprehensive explanation there.
For term true geometric counter part, it was replaced by term, datum feature simulator, in 2009 standard. You'd better go through this standard to understand...
Pmarc,
Thx! No matter whether OP knows how to deal with his problem, as a newbie, I just learned a valuable application from your post and found my ignorance in many sections of GD&T.
pylfrm,
In gabimot's idea, what it does is to control the actual local size at each cross-section. Thus it has avoided MMC perfect form control and meet Ob's requirement. Of course size tolerance does nothing with parallelism.
I don't quite get you for "VARIATION OF LOCAL THICKNESS NOT TO...