I would like to learn about different opentype features and one natural way for me would be to open existing fonts and examine them.
But when I open a typeface to see its opentype code it doesn’t appear in the “Features” under font info. Is this a deliberate decision (due to copyright issues, for example?) or can the code be viewed somewhere else in the program?
It’s because the feature code is not in the final font file. Some programs try and reverse-engineer the compiled binary tables but it will likely be incomplete and partly, it’s just guessing.
So, I advise you to skim through the resources that are available online, e.g. discussions in forums, blogs etc. Google is your friend. Plus, there’s Adobe’s OpenType Feature File Specification to start from.
Thanks for the advice, will look into it!