In MainBoss, records have field for an ID Code and Description.
This raises a question: since you can put a lot of information into the ID Code, what do you do with the Description field?
Different organizations will have different answers. One possibility is simply to leave the Description field blank. Another is to duplicate the ID code (although there's not much reason to do this).
A more interesting alternative is to use the Description field to hold useful additional information. For example, consider an Employee record. In this case, the ID Code displays the employee's name as given in the Contacts table. You might then fill in the Description field with any identification number the employee might have; this will help you tell the difference if you happen to have two employees with the same name.
As another example, consider a Units record describing a company car. While the ID Code might be the car's license plate, the Description could be something like Ford Taurus 2008, Black. Alternatively, you could reverse these two values: the type of car in the ID Code field and the license plate in the Description.
The important point is that ID Code and Description are the first two fields in almost every record, and they're often both displayed in table viewer lists. It makes sense to use these two fields to hold the information that your organization will find most useful.