While this calculation is accessible inside of Design > Calculations and by right-clicking to go to Quick Calculations > JDE > Associated Description, the easiest way to apply an associated description is a simple double-click of the column caption.
Enable the default preferences setting called "Double-click concatenates associated description" to automatically use this calculation to bring together a code column and its associated description when double-clicking the code column. This type of 'code - description' column format is common for many report writers.
Additional associated description relationships can be added by a DAS Administrator, but many associations are already mapped.