<?xml version="1.0"?> <!DOCTYPE para PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd"> <para> Effectivity attributes can be used to keep track of modifications to a document <phrase revisionflag="deleted">at the word or sentence level</phrase><phrase revisionflag="added"> as long as the number and complexity of changes is not too high</phrase>. </para>