TIdSASLServiceName - Service name for the SASL authentication mechanism.

ServiceName is an overridden TIdSASLServiceName class function that indicates the service name for the SASL authentication mechanism. 

SASL mechanism names must be registered with the IANA. The current list of registered SASL mechanisms can be located at: 

IANA Official Simple Authentication and Security Layer Mechanisms  

In TIdSASLExternal, ServiceName returns the value: 

   EXTERNAL

ServiceName is used in IsAuthProtocolAvailable to ddetermine if the current SASL authentication mechanism can be found in a list of supported authentication mechanisms.

IsAuthProtocolAvailable TIdSASLServiceName