<!-- <?xml version="1.0" ?> <!DOCTYPE appendix PUBLIC "-//KDE//DTD DocBook XML V4.2-Based Variant V1.1//EN" "dtd/kdex.dtd"> To validate or process this file as a standalone document, uncomment this prolog. Be sure to comment it out again when you are done --> <appendix id="intro-digital-audio"> <title >Introdução ao Áudio Digital</title> <para >amostragem digital, filtros, efeitos, &etc;</para> </appendix>