xmlcatalog \
    --noout \
    --del "/usr/share/xml/docbook/xsl-stylesheets-1.79.2" \
    /etc/xml/catalog
xmlcatalog \
    --noout \
    --del "/usr/share/xml/docbook/xsl-stylesheets-1.79.2-nons" \
    /etc/xml/catalog
