"They're doing something similar for geographic shape data, by attaching a document and linking to..."
Types aren't one-size-fits-all; in fact, there are several different kinds of types you can create and use in Freebase, depending on how you want users to enter information for their properties, or how you want them to relate to types that others have created. There are four basic types to be aware of when creating new types in Freebase:
Core Property Types - these are the basic properties and commonly used types, such as Topic, Person, and Location that are common across Freebase schemas.
Enumerated Types - when users fill in information for an enumerated type, they are given a list of pre-determined choices you have created rather than having a list of choices from autocomplete.
Included Types - are automatically added to a type when you first create it. An example of an included type is Topic, which is automatically added to all Freebase types. The Schema Editor provides an easy mechanism for including other types as well.
Compound Value Types - these are a little tricky, since they don't have properties like other types. Instead, they serve as a link between two other types and establish a relationship between them.
Confused? Don't worry, most of the time creating a new type is a very straight-forward process, but you should read all the topics linked above to make sure you're familiar with the different kinds of types and how they're used.
