GSUB glyph deletion

Is it possible to remove a glyph via a substitution rule using Glyphs? The afdko documentation mentions sub A by NULL;, however this results in the error ‘Unexpected “NULL” in rule substitution’ when I try it in Glyphs (3086).

I understand this is a relatively new addition to the afdko spec — is there a plan to implement it in Glyphs? (Or is it already present under a different syntax?)

See Support glyph deletion in features - #2 by GeorgSeifert.

In the meantime you can use a dummy glyph and give it Mark, Nonspacing category and subcategory, so it would be ignored when IgnoreMarks lookup flag is set.


Hi there,

I am now able to apply a GSUB ‘deletion’ using the sub A by NULL; method. I am trying this for fractions feature wherein the fraction glyph is ignored. So my method has been to use Tal Leming’s Fraction Fever and then tack on the:
sub fraction by NULL;

This seems to work on Illustrator but I have not been able to get this to work on InDesign. Is there something I can do to fix this or is this an Adobe problem?

Illustrator and Photoshop now use HarfBuzz which supports glyph deletion, while InDesign still defaults to Adobe’s layout engine(s) which do not support it. InDesign has some obscure way to enable HarfBuzz which might work around this until InDesign bites the bullet and finishes the switch.

1 Like

Thanks for like. I didn’t know this.
So Indesign contains HarfBuzz for two years now and they still don’t use it by default? What a waste.