| #### Optional Parameters In routine descriptions, optional parameters allow the application to request default behaviors by passing a default value for the parameter. The following conventions are used for optional parameters:
Convention | Value Default | Explanation
gss_buffer_t types | GSS_C_NO_BUFFER | For an input parameter, indicates no data is supplied. For an output parameter, indicates that the information returned is not required by the application.
Integer types (input) |  | Refer to the reference pages for default values.
Integer types (output) | NULL | Indicates that the application does not require the information.
Pointer types (output) | NULL | Indicates that the application does not require the information.
OIDs | GSS_C_NULL_OID | Indicates the default choice for name type or security mechanism.
OID sets | GSS_C_NULL_OID_SET | Indicates the default set of security mechanisms, DCE Security and Kerberos.
Credentials | GSS_C_NO_CREDENTIAL | Indicates that the application should use the default credential handle.
Channel bindings | GSS_C_NO_CHANNEL_BINDINGS | Indicates that no channel bindings are used.
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