To show a DokuWiki page inside an IFRAME can be done with the XHTML export:

• Standard output: https://drivrsdu.fr/toutfaux/faux:touche_tgv
• XHTML Output: https://drivrsdu.fr/toutfaux/faux:touche_tgv?do=export_xhtml

The following DokuWiki IFRAME code demo needs the Iframe plugin:
(There is a certain problem with the background of the XHTML output. Please read at the end of this page.)

The background of the XHTML export is unintentionally the background of the template of the exported page - usually the DokuWiki default template. To set your own background (maybe background=none), take a look at: IFRAME Background Tweaks via CSS Inline Style

LiveDemo for: IFrame from a page