Hans, the following sample breaks compilation with latest after release from 2021.02.05 17:45: \startbuffer[demo] <html xmlns="http://www.w3.org/1999/xhtml"> <body> <div id="in" class="section level1 frontmatter"> <h1>In</h1> </div> <div id="body" class="section level1 bodymatter"> <h1>Body</h1> </div> </body> </html> \stopbuffer \startxmlsetups xml:initialize \xmlsetsetup{#1} {html|body|div|h1} {xml:*} \xmlsetsetup{#1} {[contains(@class,'frontmatter')]} {xml:frontmatter} \xmlsetsetup{#1} {[contains(@class,'bodymatter')]} {xml:bodymatter} \stopxmlsetups \xmlregistersetup{xml:initialize} \startxmlsetups xml:html \xmlflush{#1} \stopxmlsetups \startxmlsetups xml:body \xmlflush{#1} \stopxmlsetups \startxmlsetups xml:frontmatter \startfrontmatter \xmlflush{#1} \stopfrontmatter \stopxmlsetups \startxmlsetups xml:bodymatter \startbodymatter \xmlflush{#1} \stopbodymatter \stopxmlsetups \startxmlsetups xml:h1 \xmlflush{#1} \stopxmlsetups \starttext \xmlprocessbuffer{main}{demo}{} \stoptext Current latest from 2021.02.13 00:28 complains about argument of \xmlw having an extra }. I think this may be a bug in ConTeXt. Many thanks for your help, Pablo -- http://www.ousia.tk