Compile other documents, yet space indices are themselves projectdoc documents. So they can be tagged and grouped.
Instances for homepages of document types to group and collect document instances. Any page that does not belong a document type, that is is a singular page, may be represented by an instance of the Space Index doctype.
An alternative would be to use a blank page. The Space Index doctype provides document properties to query and display space indices (with their short description) more easily.
The document type Space Index provides the following properties:
Please note that only information about specific properties is provided here. Common document property used by all document types are documented by Document Properties.
Subordinate Space Indices
List of space indices related to this subject.