% arara: pdflatex
% arara: pdflatex
% arara: makeglossaries
% arara: pdflatex
\documentclass{article}

\usepackage[colorlinks]{hyperref}
\usepackage{glossaries-extra}

\makeglossaries

\GlsXtrEnableEntryCounting
 {abbreviation}% list of categories to use entry counting
 {2}% trigger value

\newabbreviation{html}{HTML}{hypertext markup language}
\newabbreviation{xml}{XML}{extensible markup language}
\newabbreviation{css}{CSS}{cascading style sheet}

\newglossaryentry{sample}{name={sample},description={sample}}

\begin{document}
This is a sample document to entry counting. The entry counting
has been enabled on the \texttt{abbreviation} category.
This means that abbreviations will only be added to the glossary 
if they have been used more than $n$ times, where in this 
document $n$ has been set to
\glsgetcategoryattribute{abbreviation}{entrycount}.
Entries in other categories behave as normal.


Used once: \gls{html}.

Used twice: \gls{xml} and \gls{xml}.

Used three times: \gls{css} and \gls{css} and \gls{css}.

Used once but this entry is in the ``general'' category
which doesn't have the ``entrycount'' attribute set:
\gls{sample}.

\printglossaries

\end{document}