Fonts & Character Sets ⇒ Automatic ordinals with fontspec and opentype?

[hesitz]

I'm using xetex and fontspec with Adobe's opentype Garamond Premier Pro font.

I think there must be some way to have it automatically superscript the endings in ordinals like '1st', '2nd', '3rd', etc., but I can't figure it out.

I turned on feature, 'VerticalPosition=Ordinal' in the font specification. That doesn't work properly. It does superscript ordinals properly. But it also superscripts all lower case letters in every word, regardless of whether it's an ordinal or not, and regardless of whether they are trailing or not.

Is there some other simple switch to turn it on that I'm missing? Or is this some kind of mapping or encoding problem?`

Or maybe it's just a bug. I notice that the example for VerticalPosition=Ordinal in most recent fontspec manual pdf at bottom of p. 22 is not rendered properly, though the error their is different from what I'm seeing:
http://www.ctan.org/tex-archive/macros/ ... ntspec.pdf

Thanks,

Herb