Parameter “Remove all, except ...”

Is there a syntax to use the Remove parameters (Remove glyphs, Remove classes, Remove feature) removing all except something?

For glyphs, there is the Keep Glyphs parameter which does what you want.

For automatic features, you do not need to do anything, because if the triggering glyphs are gone, the feature disappears as well. If it doesn’t, you can force it with the Update Features parameter. Manual features you still have to list one by one.

You do not really need to take care of classes, because IIRC, unused classes are ignored anyway in compilation.

Thanks. It reports an error if there is a class and the corresponding glyphs are missing.

I see. Not an automated class I guess. If you remove glyphs, you need to update the class code too. I think the parameter for that is called Replace Class.

What is an automated class? Never understood how this works.

Some classes can be kept up to date automatically.

All, Lowercase, Uppercase, AllLetters are the relevant ones for Latin.