Page
The simplest form of a POSHDOC is a single HTML file — a POSHDOC page.
Pages are useful for short plain text documents like notes or messages where semantic markup is wanted. Since no media can be included, the utility of pages is limited.
If a POSHDOC page is instantiated in a file system or accessible via an URL, the basename of the file without the filename extension should correlate to its title.
A directory hierarchy might hold a collection of interlinked POSHDOC pages, this would be called a POSHDOC page collection.