Identifier attribute

The identifier attribute can be used on a component of a group. The identifier indicates the components that can be used to identify the type to which a data object belongs. All the components, from the first, up to and including the component with the identifier attribute, are used for type identification.

When this data is validated, it knows that, when it reaches the identifier, it has found a specific group. That group, therefore, is known to exist, even if part of the group following the identifier is missing. The map designer documentation discusses how data validation occurs.

The identifier attribute is also useful when identifying an object of a partitioned group. For information about using an identifier with partitioned data, see "Partitioning".

In a component list, there can be only one identifier attribute.