### 3.3 Optional Parameters ¶

Various parameters are described as optional. This means that they follow a convention whereby a default value may be requested. The following conventions are used for omitted parameters. These conventions apply only to those parameters that are explicitly documented as optional.

- gss_buffer_t types. Specify GSS_C_NO_BUFFER as a value. For an input parameter this signifies that default behavior is requested, while for an output parameter it indicates that the information that would be returned via the parameter is not required by the application.
- Integer types (input). Individual parameter documentation lists values to be used to indicate default actions.
- Integer types (output). Specify NULL as the value for the pointer.
- Pointer types. Specify NULL as the value.
- Object IDs. Specify GSS_C_NO_OID as the value.
- Object ID Sets. Specify GSS_C_NO_OID_SET as the value.
- Channel Bindings. Specify GSS_C_NO_CHANNEL_BINDINGS to indicate that channel bindings are not to be used.