Add perthousand and percent to fractions feature

I apologize if a similar question has been asked in the past. I am a complete xml neophyte. What do I have to change in my Glyphs set up so that when Glyphs auto-builds features, it includes perthousand and percent in the fractions feature?

I am not sure it should be included in the frac feature:

And the automation does not depend on the Glyphdata XML. But you could simply make your /zero.numr/fraction/zero.dnom look like /percent.

Percent and perthousand aren’t fractions, but they can be entered the same way (ie. 0/0) and are commonly included in the fractions feature…

Neither are percent and perthousand, numbers. In all the years I’ve been working with type and fonts, making one of those glyphs using a zero fraction number would never have occurred to me. I was trained to design them using the /o as a basis, and I believe that is the correct way.

Look at the fractions feature in fonts from the major foundries. Percent and perthousand are included as “sub zero slash zero by percent;” and sub zero slash zero zero by perthousand;".

I wasn’t looking to debate whether they should be or not. That really is a choice for each individual designer. I was simply asking what I had to do to my set up so those 2 glyphs would be included when Glyphs auto-builds features.

I see what you are wanting to do now; sub a percent or perthousand glyph for keyboard entries where access could be a problem. I thought you were attempting to build a percent glyph using the fraction feature.