# Add entry to the list of abbreviations but not to the index

\documentclass{memoir}

\usepackage[xindy,abbreviations,nomain,nonumberlist]{glossaries-extra}

\makeglossaries
\makeindex

\glssetcategoryattribute{abbreviation}{dualindex}{true}
\newabbreviation{html}{html}{hypertext markup language}
\newabbreviation{ac}{ac}{ante correctionem}

\begin{document}
\gls{html}
\printglossaries
\printindex
\end{document}


I would like to suppress the indexing of ac, but keep it in the list of abbreviations. Currently it appears in the index under the page in which \glsadd is called.

Just assign it a different category attribute (that doesn't have the dualindex attribute set). For example:

\documentclass{memoir}

\usepackage[xindy,abbreviations,nomain,nonumberlist]{glossaries-extra}

\makeglossaries
\makeindex

\glssetcategoryattribute{abbreviation}{dualindex}{true}
\newabbreviation{html}{html}{hypertext markup language}
\newabbreviation[category=nondual]{ac}{ac}{ante correctionem}

\begin{document}
\gls{html}

Since there's no abbreviation style explicitly set for this category, it will fall back on the style for the abbreviation category.