# Kerning exception and class pair both applied in exported OTF (exception in separate lookup)

**URL:** <https://forum.glyphsapp.com/t/kerning-exception-and-class-pair-both-applied-in-exported-otf-exception-in-separate-lookup/37450>\
**Category:** Glyphs\
**Tags:** bug\
**Created:** [October 12, 2026, 5:25am UTC](https://forum.glyphsapp.com/t/kerning-exception-and-class-pair-both-applied-in-exported-otf-exception-in-separate-lookup/37450 "2026-10-12T05:25:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![oneweioranother](https://forum.glyphsapp.com/user_avatar/forum.glyphsapp.com/oneweioranother/32/273_2.png) [@oneweioranother](https://forum.glyphsapp.com/u/oneweioranother)\
**Post date:** [October 12, 2026, 5:25am UTC](https://forum.glyphsapp.com/t/kerning-exception-and-class-pair-both-applied-in-exported-otf-exception-in-separate-lookup/37450/1 "2026-10-12T05:25:01Z")

</div>

3.5.1 (3534), exporting a static OTF.

I have a kerning exception`/seven.numr/fraction` = −310. The right kerning group of `seven.numr` also has a class pair against `fraction` of −290. Edit view correctly shows −310. In the exported font the two values are added, so InDesign and HarfBuzz apply −600.

The compiled GPOS `kern` feature has two pair lookups, and both are registered for DFLT and latn:

| Lookup | Subtable | Value |
| --- | --- | --- |
| 0 | Format 1 (glyph pair) | `seven.numr fraction` −310 |
| 1 | Format 2 (class pair) | `@[seven.numr group] fraction` −290 |

The exception and the class pair are in different lookups, so the exception doesn’t override the class pair and both apply.

The right group containing `seven.numr` mixes Common-script glyphs (numerators, superiors, asterisk, degree, registered, trademark) with Latin-script glyphs (ordfeminine, ordmasculine). Seems like Latin members cause the group’s class kerning to go into a separate script-specific lookup from the Common-script exception.