Define the default search space for attachment index spaces.
Index spaces are meant to collect common configuration for spaces. This includes space properties and homepages for doctypes.
A type doctype is a doctype that is used to categorize one other doctype. The doctype defines a document property named Type (this is a naming convention).
For instance a resource type doctype defines types for the resource doctype.
On a type document typically all document instances of the given type are listed. So a type document instance is simply a view on your documents.
For this example a resource type document is named Specification.
Each type document instance has a section called Resources of this Type.
In this section there is an instance of the Display Table Macro that automatically lists all resource documents of this resource type.
In this example the document named Specification lists all resource documents of type Specification.
Since index spaces are used by multiple spaces, documents from all this spaces should be listed. Per default only the document instances of the index space itself are listed (which are typically none).
This tip shows how to fix this easily.
