key part

Every rule instance and data instance defined through a form has one to three key parts, the fields you complete during the Create form.

Which properties form the key and in which order for objects of a specific class are determined in the class rule:

For a data instance, these fields in combination uniquely identify the instance within the class. For example, the Data-Admin-OrgDivision class has two key parts, labeled Organization Name and Division Name on the Division form. Only one instance of this class with Acme.org as the first key part and Marketing as the second key part can exist in your system.
For a rule instance, these fields in combination uniquely identify the instance, within a rulset, version, circumstance, and other qualifiers. For example, the Property form has two key parts labeled Applies To and Record Identifier. Your system may contain multiple properties with Assign- as the Applies To key part and Payload as the Name key part, in different rulsets or versions.

If an object has only a single key part, that value is often called the name of the object.