Plus Size Petite ??? WTH?

What the hell is "Plus Size Petite"
Isn't that contradictory?

And why are different manufactures using S, M, L, XL, etc yet the "Dress Size" equivalents not to mention actual measurements are all over the place and 'Do NOT' match?

OK, It seems this sizing conversion is more complex then I thought.

Looks like its back to trial and error!
Well not that I've really gotten any thing of my own yet,
except......