You may need to manage the codes for almost all apps for customization. Most of the drop-down lists are filled with code database.

For example, while adding a new Contact to the system, you may see a PhoneType Field on the Phone page. The necessary values within the available options are coming from the Codes database.

If you need to see different options in the list, the desired changes can be made through Codes functionality.

You can also add new CodeType similar to PhoneType while developing any new functionality.