The item-ID and each attribute of the file-defining item contain information that points to and describes the lower level dictionary file or data file. Because it has a D dictionary code, the file-defining item is sometimes referred to as a D-pointer.
The item-ID of the attribute-defining item is the attribute name. The next value of an attribute-defining item is a number n which refers to the nth attribute in the item. For example, an attribute count of 5 refers to the fifth attribute in the data item.