Non-letters are not being processed in positional alternates

Trying to add an underline to various glyphs using positional alternates (.isol .init .medi and .fina) and running into an issue of the alternate forms only working with glyphs set as category Letter. If it is a non-letter glyph with categories such as a Number or Punctuation then it does not work, however, if I manually change to Letter then it works.

  1. Is there a reason non-letters aren’t being processed or is it a bug?
  2. Does changing the category have an impact on the outputted fonts or is it a way of sorting in Glyphs?

You mean those are not picked up in the automatic feature code?

Here is an example. The underline gets added (sub A by A underline.2) when a stylistic set is enabled. The .init .medi .fini all work when it is all letters AAA but AA2 doesn’t (example 1). If 2 is changed from Number->Letter in the category, then it works (example 2)

Example 1 (2 is category Number)

Example 2 (2 is category Letter)

Can you check the difference in opentype code?

Not entirely sure what you mean.
The opentype code doesn’t change between the two examples. The only thing that I manually change is the category.

Can you show the OpenType code or send me the .glyphs file?

Just realizing my mistake :man_facepalming: was using the @AllLetters class which obviously means all LETTERS…switched it to @All class instead to include everything, and it works. Sorry for the trouble.