The Custom tab of the Properties dialog box sometimes contains predefined properties. These properties are available in the property Name list, and have a preset name and data type. You can add them to the object individually and set the value.
If you need a property for a harness component that is not predefined by Cable and Harness, you can create a custom property. To create a custom property, you name the property and set its data type and value. Once the property is fully defined, it is added to the property Name list on the Custom tab. The property is also available in the Name list within the same part file or harness assembly for use on other harness objects.