System field. A system field is a standard Siebel field for a business component that represents the data from the system columns.

Custom field. A custom field is a field that you can create to extract data from a field that exists in the Siebel business component.

Calculated field. A calculated field is a Siebel field that derives its value from a calculated expression. You import Siebel calculated fields as custom fields.

Formatted field. A formatted field is a field that you can create and use to extract data in the configured format. When you import a Siebel business component as a source definition, you can select the formatted fields and the PowerCenter Integration Service can read data of the formatted fields in the configured format. When you configure any field to retrieve data in a specific format, the datatype for the field changes to DTYPE_TEXT in the Siebel source definition.