Image reference () cannot have an extension; the proper format is inferred by the output type to generate. Image reference () format must not be specified; it is inferred by the output type to generate. Filename () has role="directory"; use class="directory" Link () element must have a content; or use xref to auto-generate the linking text. Callouts with screenco are not supported; use screen and co instead. Callouts with programlistingco are not supported; use programlisting and co instead. Callouts on graphics are not supported. Invalid edition value (); must be either 'online' or "print". Invalid os value (); must be either 'freebsd8', 'freebsd9' or 'freebsd10'. There must be a title either in book or in bookinfo. There must be a title either in article or in articleinfo. There must be a title either in chapter () or in chapterinfo. There must be a title either in sect1 () or in sect1info. There must be a title either in sect2 () or in sect2info. There must be a title either in sect3 () or in sect3info. You cannot use both colname and spanname attributes on table entries. @linkend on firstterm must point to a glossentry. @linkend on footnoteref must point to a footnote. @linkend on glossterm must point to a glossentry. @linkend on synopfragmentref must point to a synopfragment. @otherterm on glosssee must point to a glossentry. @otherterm on glossseealso must point to a glossentry. A termdef must contain exactly one firstterm The number of seg elements must be the same as the number of segtitle elements in the parent segmentedlist annotation must not occur in the descendants of annotation caution must not occur in the descendants of caution important must not occur in the descendants of caution note must not occur in the descendants of caution tip must not occur in the descendants of caution warning must not occur in the descendants of caution caution must not occur in the descendants of important important must not occur in the descendants of important note must not occur in the descendants of important tip must not occur in the descendants of important warning must not occur in the descendants of important caution must not occur in the descendants of note important must not occur in the descendants of note note must not occur in the descendants of note tip must not occur in the descendants of note warning must not occur in the descendants of note caution must not occur in the descendants of tip important must not occur in the descendants of tip note must not occur in the descendants of tip tip must not occur in the descendants of tip warning must not occur in the descendants of tip caution must not occur in the descendants of warning important must not occur in the descendants of warning note must not occur in the descendants of warning tip must not occur in the descendants of warning warning must not occur in the descendants of warning caution must not occur in the descendants of caption equation must not occur in the descendants of caption example must not occur in the descendants of caption figure must not occur in the descendants of caption important must not occur in the descendants of caption note must not occur in the descendants of caption sidebar must not occur in the descendants of caption table must not occur in the descendants of caption task must not occur in the descendants of caption tip must not occur in the descendants of caption warning must not occur in the descendants of caption caution must not occur in the descendants of equation equation must not occur in the descendants of equation example must not occur in the descendants of equation figure must not occur in the descendants of equation important must not occur in the descendants of equation note must not occur in the descendants of equation table must not occur in the descendants of equation tip must not occur in the descendants of equation warning must not occur in the descendants of equation caution must not occur in the descendants of example equation must not occur in the descendants of example example must not occur in the descendants of example figure must not occur in the descendants of example important must not occur in the descendants of example note must not occur in the descendants of example table must not occur in the descendants of example tip must not occur in the descendants of example warning must not occur in the descendants of example caution must not occur in the descendants of figure equation must not occur in the descendants of figure example must not occur in the descendants of figure figure must not occur in the descendants of figure important must not occur in the descendants of figure note must not occur in the descendants of figure table must not occur in the descendants of figure tip must not occur in the descendants of figure warning must not occur in the descendants of figure caution must not occur in the descendants of table equation must not occur in the descendants of table example must not occur in the descendants of table figure must not occur in the descendants of table important must not occur in the descendants of table informaltable must not occur in the descendants of table note must not occur in the descendants of table tip must not occur in the descendants of table warning must not occur in the descendants of table caution must not occur in the descendants of footnote epigraph must not occur in the descendants of footnote equation must not occur in the descendants of footnote example must not occur in the descendants of footnote figure must not occur in the descendants of footnote footnote must not occur in the descendants of footnote important must not occur in the descendants of footnote indexterm must not occur in the descendants of footnote note must not occur in the descendants of footnote sidebar must not occur in the descendants of footnote table must not occur in the descendants of footnote task must not occur in the descendants of footnote tip must not occur in the descendants of footnote warning must not occur in the descendants of footnote sidebar must not occur in the descendants of sidebar