Final answer:
A composite key allows using a field as a unique identifier in place of the sys_id when dealing with Reference fields.
Step-by-step explanation:
In certain systems or databases, a field can be used as a unique identifier in place of the sys_id when dealing with Reference fields by making use of a composite key.
A composite key is formed by combining two or more fields to create a unique identifier. For example, if you have a table with a Reference field and you want to use a different field as the identifier, you can create a composite key by combining the original Reference field with the desired field. This allows you to use the composite key as a unique identifier instead of the default sys_id field.
Using a field as a unique identifier in place of the sys_id can be helpful in scenarios where you want to use more meaningful or relevant identifiers for your records.