• When — The system evaluates the when condition rule specified by the When key field. If the condition evaluates to true, the system returns an exception with the specified data. If false, the system continues evaluating the next when condition rule in the list. If all specified when condition rules return false, the system returns the normal response data specified on the Parameters tab to the client application. Use this feature to extend the normal set of fatal error conditions that result in exceptions being returned to the client.
• Queue When — The system evaluates the when condition rule specified by the When key field. If the condition evaluates to true, the system queues the service request and returns a Pega Platform-specific SOAP fault that includes the queue item ID of the service request. To customize the fault reason string provided in the SOAP fault, select Constant from the Map from field and enter a string such as, "Object was locked - queued for retry." (The queue item ID is provided in the SOAP fault detail string, so you do not need to explicitly include it in the mapping.) Note that if you configure a Queue When condition, you must specify a request processor in the Request processor field on the Service tab. For more information, see Pega Community article Configure a service to queue a failed service request for another attempt.
• Mapping Error — If an error occurs while mapping incoming data from the request message to the clipboard, the system returns an exception with the specified data. If the list of response conditions does not include an entry for mapping errors, the system returns a standard exception to the client application.
• Security Error — If an error occurs while authenticating the application client credentials, the system returns an exception with the specified data. If the list of response conditions does not include an entry for security errors, the system returns a standard exception to the client application.
• Service Error — If a service error occurs, the system returns an exception with the specified data. If the list of response conditions does not include an entry for service errors, the system returns a standard exception to the client application.
  Note: It is a best practice to configure the error conditions to ensure that the system notifies an administrator about the error.

Specify the source of the SOAP fault reason value:

• Clipboard — Map the SOAP header value from a property on the clipboard
• Constant — Provide the literal value to send as the value of the SOAP header.

• If the Map From value is Clipboard, identify the property that is the source of the value.

For an example of this facility, see Pega Community article How to customize SOAP fault messages.