install-catalog --remove /etc/sgml/sgml-docbook-dtd-3.1.cat \
		/usr/share/sgml/docbook-sgml-3.1/catalog > /dev/null 2>&1 || true
install-catalog --remove /etc/sgml/sgml-docbook-dtd-$1.cat \
		/etc/sgml/sgml-docbook.cat > /dev/null 2>&1 || true
