Most of Dynamics AX data lookups display a list of records where the first column always contains a value, which is returned to a calling form. The first column in the lookup normally contains a unique record identification value, which is used to build relations between tables.
For example, customer lookup displays customer account number, customer name, and some other fields; inventory item lookup displays item number, item name, and other fields. In these examples and most other cases, it is OK because unique record identification value is self explanatory.
But in some cases, the record identifier can be not so user-friendly and may require showing additional information on the parent form. One of the ways of solving such issues is to create a lookup, which is actually based on the record identifier, but upon user selection returns the record description or other more explanatory field. In the standard Dynamics AX application, you can find...