Germandbls and germandbls

Thank you for your help!

That is only the case in the classic Adobe Composer. Has nothing to do with your font. Switch to the World-Ready Composer, and it works.

I usually even put the Germandbls directly there.

Why does the tutorial use germandbls.calt? Two reasons:

  1. There is an impossibly rare (perhaps even only theoretical) case where that may cause problems in reverse-engineering the character string when you select and copy text in a PDF in certain PDF viewers on some operating systems. But character streams in PDFs are so problematic in themselves, I believe that is really the least problem.
  2. Principally, one encoded glyph should not be substituted for another encoded glyph. There are exceptions to the rule, i.e., some OT features may do that, but not calt or case. So if you want to stay 100% true to the spec, you shouldn’t do that. But still, current OT implementations have no issues if you do.

Yes. Glyphs should do it like this automatically.

It must be my font then, even with World-Ready Composer changing case from lc to uc results in SS.

This is what my feature panel looks like in the compiled font.

Which version of InDesign are you running?

15.1.3