There are several sections that appear in all KDE DocBook files, even though they are not required by DocBook itself:
<!ENTITY % addindex "IGNORE"> <!ENTITY % English "INCLUDE">
This appears in the prologue immediately after the FPI. See the section called “The Prologue” for more details about this section.
<!-- TRANS:ROLES_OF_TRANSLATORS -->
This appears after the
<authorgroup>element, and is a required placeholder for use in translation (also known as “i18n” from the number of letters between the first and the last of the word “internationalization”).