nsgmls -sE 65533 ../../LDP/howto/docbook/rpmupgrade.sgml/rpmupgrade.xml 2>nsgmls.err | tee nsgmls.out
# nsgmls -sE 65533 -c /usr/share/sgml/docbook/xml-dtd-4.1/docbookx.dtd ../../LDP/howto/docbook/rpmupgrade.sgml/rpmupgrade.xml 2>nsgmls.err | tee nsgmls.out
tail nsgmls.err
nsgmls -sE 65533 -c /usr/share/sgml/docbook/xml-dtd-4.1/docbookx.dtd ../../LDP/howto/docbook/rpmupgrade.sgml/conventions.xml 2>nsgmls2.err | tee nsgmls2.out
tail nsgmls2.err