I am using the XeTeX engine in order to compile a document based on a class of my own, and the package fontspec to select the face families and features. Though this is not relevant for my question, just with the aim to be more concrete, let me say that for the sans face I am using Formata (from Adobe). This family comes in different .otf files, with the root name Formata, in such a way that the *-Regular file (and *-Light as well, this being just about weight series) includes only the "non-expert" types, small caps and text figures being included in files *-RegularSC and even another, *-RegularExpert.
I have no problem about small caps thanks to the fontspec key SmallCapsFont, but I'd like to have text figures as my default selection for numerals. Of course I have Numbers=OldStyle set in my \defaultfontfeatures, but this won't do. Is there a way that I can get to the numerals in the "expert" files without having to switch through \textsc?
Moreover, the Formata family includes a condensed face in a file *-Condensed (together with all shapes and weight series). Is there a switch to have this loaded without having to resort to fontspec's \newfontfamily or \newfontface?
Well, my priority is on the numerals-related question, but just to not open another post, I thought the latter would be appropriate here, too.
Best Answer
Many tools can let you inspect the features for OTF fonts (and there's often a documentation, too).
For example, you can use
otfinfo:This font has numeral-related features, namely
dnom,frac,lnum,numr,onum,ordn, etc.The
fontspecmanual will give you the keys to use them, or you can use them directly using theRawFeatureskey.