ALFOX ERP II's data dictionary is at the meta-data layer, and knows how to access data and how data is related.

The data dictionary contains definitions of a data entity (type, validation, etc.), how it is displayed (label on screens and reports, help, display sequence and position relative to other fields), and the display rules. Security and access rules are also maintained here.

The data dictionary is 'active', meaning it is used at runtime and context sensitive. For example: it 'knows' that an over-the-counter sale does not have a payment term and does not display it. However if you change the transaction type to a standard order, a payment term becomes a mandatory part of the transaction.

The Data Dictionary is user-extensible and can include user specified rules and information.