Parts

<..TeX4ht parts..>
 \Def:Section\Part{}{#1}
 -_-_-

<..non-html TeX4ht parts..>
 \Configure{Part}{}{}{%
    \bgroup
       \:clearpage \:HPageBeforePart       \ChapterFonts \bf
       \headline={\hfil}%
       \footline={\hfil}%
       \baselineskip=1.3\baselineskip
       \leftskip=\z@ plus 0.5\hsize    \rightskip=\leftskip
       \leavevmode\vfill  \leavevmode\break
       \def\InsertTitle{\uppercase}%
 }{%
       \vfill \vfill \vfill \vfill
       \leavevmode\break   \:HPageAfterPart  \newpage      \IgnorePar
    \egroup      \ignorespaces
 }
 -_-_-

<..TeX4ht parts..>+
 \def\OddPartHPage{%
    \def\:HPageBeforePart{\ifodd \pageno \else \leavevmode\ \newpage\fi}%
    \def\:HPageAfterPart{\newpage\leavevmode\ }}
 \def\:NoOddChapterHPage{\def\:HPageBeforePart{}\def\:HPageAfterPart{}}
 \:NoOddChapterHPage
 -_-_-