DGIWG defines a number of specific lists of information elements that can be combined with the models in product specifications and application schema. Where possible DGIWG lists are handled as registers in compliance with the ISO standard 19135 on registration for geographic information items. A number of different registers are defined because registers provide a well-structured way of maintaining a list. In compliance with the ISO standard, all registered items have unique identifiers and dates that indicate when the item was defined and deleted or superseded. Registers also allow for cross-referencing to other external registers maintained by separate organizations. This capability promotes interoperability since the correspondence of registered items from one register to another can be easily determined. Source identification "authoritative referencing" also supports maintenance since versions of external referenced items can be tracked.
Different registers address different types of information elements. A registry is scoped to a specific type of information element. Items of that type may be partitioned into separate registers. Several DGIWG registries include more than a single register.
Registers are maintained for the following information elements: