This DokuWiki-plugin was originally created to include an approved html-form into a wiki-page. But it can also be used to insert safely php into DokuWiki-pages.
Please notice that this plugin is a fork of the incl_form-plugin, which can be found at https://www.dokuwiki.org/plugin:incl_form. The documentation of the new plugin is available at https://www.dokuwiki.org/plugin:inclform. There were only improvements to adapt the plugin to recent DokuWiki- and PHP-versions, it has the same functionality as the orginial incl_form-plugin.
The original author is Kite, kite@puzzlers.org