Traditional data dictionaries are just a laundry list of "information elements".

There is usually the following information:

• name

• type information (char[20]).

• human-readable description.

• constraint information.

It may look like an XML Schema types but:

• complex types are aggregates and data dictionaries usually aren't.

• complex types have content models that describe child occurrence.

• complex types have both children and attributes.

Keep this in mind as we proceed.