A delegate space contains space properties and doctype homepages. Spaces related by delegation simply reuse information.

Think of a delegation space as a associated space that contains information on behalf of the delegating space.

For search macros (such as the Display Table Macro) spaces can be connected as search spaces. If information is queried in one space, all its declared search spaces are also automatically included.

Use an index space to define space properties that should be applied to all delegating spaces (that is: a space setting the index space as a delegate-space Delegate Space).

For instance setting extract-short-description-from-metadata-table Extract Short Description From Metadata Table to true will render the short description of a document in front of the document properties table. Setting this property in an index space will automatically apply this render rule to all documents of all delegating spaces.

Another example is configuring the metadata sets for HTML metadata in a central index space. The configuration is reused by all delegating spaces.

So any space property of a delegate space is available in a delegating space, if this property is not overridden.

Additional to space properties, index spaces provide home pages for organizing document types such as subjects, categories, or tags. These organization schemes require work to create and are often quiet similiar (at least for the generic types) within an organization. Think of resource types like book or article, module types such as reference or figure, or the expected experience level of the audience, such as beginner or expert.

Documents describing external resources (such as books, organizations, or people) may be of value for more than one space. These documents should be stored in attachment spaces. Their metadata will make it easy to compile lists of related information.

Resources that describe books or articles may be collected in a single library space. A particular resource may deal with more than one domain. By tagging the resource with the name of the domain, resources can be easily compiled using a search macro as the Display Table Macro. The same goes with organizations and people collected in an address book.