A directory hierarchy containing POSHDOC documents and optionally POSHDOC pages as well as utility HTML files, is called a POSHDOC collection.

Typically the top level directory is a POSHDOC document, the title of which is the name of the collection.

POSHDOC collections correspond to traditional Wikis or to complex technical/scientific documents.

ToDo: expand on properties/benefits of POSHDOC collections, relate to POSHDOC page collections, siblings are sections, subdirectories are subsections