# Comma bug in the realscripts package?

I am using TeXLive 2019. A comma in the superscript while using the realscripts package appears in the main text instead of the superscript. I have noticed this issue when using Libertinus Serif as well as STIX Two Text. MWE:

\documentclass{minimal}

\usepackage{realscripts}

\newfontfamily\stt{STIX Two Text}

\newfontfamily\ls{Libertinus Serif}

\begin{document}

{\stt test\textsuperscript{a,*}}

{\ls test\textsuperscript{a,*}}

\end{document}


Not sure if this is a bug. Any help will be appreciated.

• Unrelated, never use the minimal class for minimal examples, use something standard like article – daleif Oct 8 '19 at 6:01

With realscripts, superscripts are realized by doing

\addfontfeature{VerticalPosition=Superior}


provided the font has the sups feature.

How does such a feature work? It essentially provides a table of substitutions:

• if a is requested, then the lookup table will point to a different glyph than a normal a, appropriate for superscripts;
• if a character is requested that has no entry in the lookup table, the standard glyph is used.

This is precisely what happens in your setup: the fonts don't have a comma in “vertical superior” position.

• Ok thanks. This clears things up. I will use \textsuperscript*{} when I need to use commas. Not sure if you are the author of this package, but wouldn't it be better if a fake superscript was used as backup instead of the standard glyph? – latex_guy Oct 8 '19 at 7:40
• @latex_guy The feature is applied as a whole, not “character by character”. – egreg Oct 8 '19 at 7:42