% \enabletrackers[xml.entities]

\startbuffer[test]
<a>
   test &sim; test
   test &xxx; test
   test &zzz; test
</a>
\stopbuffer

\startxmlsetups xml:testsetups
    \xmlsetsetup{#1}{a}{xml:*}
\stopxmlsetups

\xmlregistersetup{xml:testsetups}

\startxmlsetups xml:a
    \xmlflush{#1}
\stopxmlsetups

\xmltexentity{sim}{\getglyph{name:texgyretermesmath}{\char"223C}}

\starttext
    \xmlprocessbuffer{main}{test}{}
    \xmltexentity{xxx}{\getglyph{name:texgyretermesmath}{\char"223D}}
    \xmltexentity{zzz}{\getglyph{name:texgyretermesmath}{\char"223A}}
    \xmlprocessbuffer{main}{test}{}
\stoptext
