Understanding System ID Assignment
When you open the Add a Person component, the system requests a person ID. You can assign IDs two ways:
Automatically
If you use automatic ID assignment, the system adds IDs sequentially as you add new people.
The system maintains the last assigned ID on the Installation Table - Settings and Defaults page.
Manually
You enter the IDs, using any system that you choose for the organization. With manual entry, you don't need to assign IDs sequentially.
Assigning IDs manually is the only way that you can include alphabetical characters in the IDs.
Note: To avoid maintaining two different sets of IDs, you should either always assign them manually or always let the system assign them.