[XeTeX] on fontspec 1.10

[Pablo Rodríguez]

After paging through fontspec.pdf, I wonder whether there is a method to
switch a feature (such as UppercaseSmallCaps) without having to mention
the font. This would be very useful to switch fonts in documents only once.

I have used UppercaseSmallCaps with GFS Didot (the roman font) for
headers in a document, but for some strange reason, fontspec gives the
following messages:

Package fontspec Warning: OpenType feature 'Letters=UppercaseSmallCaps'
(+c2sc) not available in font "GFSDidot-Bold" at 8.0pt, script 'Latin',
language 'Default' on input line 178.


Package fontspec Warning: OpenType feature 'Letters=UppercaseSmallCaps'
(+c2sc) not available in font "GFSDidot-Italic" at 8.0pt, script
'Latin', language 'Default' on input line 178.


Package fontspec Warning: OpenType feature 'Letters=UppercaseSmallCaps'
(+c2sc) not available in font "GFSDidot-BoldItalic" at 8.0pt, script
'Latin', language 'Default' on input line 178.

Couldn't be this warning be avoided when the fonts are not invoked?

Thanks,


Pablo