The idea behind CMSimple is both simple and ingenious: All content is stored in a single html file "content.htm". CMSimple creates, based on the headings h1-h3, the individual pages and the navigation menu (table of contents).
CMSimple is an online CMS. The content is stored in the content.htm, page-related data in the pagedata.php. When you save a page, CMSimple automatically synchronizes pagedata.php.
Therefore both files, content.htm and pagedata.php, never should be edited offline in an code editor, because in this case the files maybe are not synchronized.
2 plugins, that store data in the pagedata.php, are already included in the standard scope of CMSimple: meta_tags and page_params.
With meta_tags you can assign meta tags for a CMSimple page , such as your own keywords, anr own page title and a custom page description. These meta tags are important for SEO (Search Engine Optimisation) of your site.
With page_params you can assign an alternative page template, you can remove the page from the navigation menu (hide), redirect a page (external or internal), etc.