# Opc.UaFx.Classic

> Reference: All types in the namespace Opc.UaFx.Classic of Opc.UaFx.Advanced v2.59.

| Type | Description |
|---|---|
| [OpcClassicApplicationDescription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicapplicationdescription/) | Represents the description of an OPC Classic server identified by its class identifier and program identifier on a host. |
| [OpcClassicApplicationDescriptionCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicapplicationdescriptioncollection/) | Represents a collection of [OpcClassicApplicationDescription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicapplicationdescription/) instances keyed by their [ClassId](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicapplicationdescription/members#classid). |
| [OpcClassicAuthenticationLevel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicauthenticationlevel/) | Defines the supported authentication level to control how much security a client or server wants from its SSP. |
| [OpcClassicAuthenticationService](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicauthenticationservice/) | Defines authentication services by identifying the security package that provides the service, such as NTLMSSP, Kerberos or Schannel. |
| [OpcClassicAuthorizationService](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicauthorizationservice/) | Defines what the server authorizes. |
| [OpcClassicDataAccessOptions](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicdataaccessoptions/) | Provides a set of options which apply to the communication with the data access layer of OPC Classic. |
| [OpcClassicEndpointDescription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicendpointdescription/) | Represents an endpoint of an OPC Classic server: the server and the interface specifications to use to communicate with it. |
| [OpcClassicEndpointDescriptionCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicendpointdescriptioncollection/) | Represents a collection of [OpcClassicEndpointDescription](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicendpointdescription/) instances. |
| [OpcClassicIdentity](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicidentity/) | Represents the identity of a user used to authenticate at the host of an OPC Classic server using DCOM. |
| [OpcClassicImpersonationLevel](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicimpersonationlevel/) | Defines the degree of authority the application grants other applications to use its identity when it calls them. |
| [OpcClassicInterface](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterface/) | Represents an interface specification of OPC Classic (e.g. OPC Data Access 2.0) which an OPC Classic server implements (see [OpcClassicInterfaces](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterfaces/)). |
| [OpcClassicInterfaceCategory](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterfacecategory/) | Specifies the category of an interface specification of OPC Classic. |
| [OpcClassicInterfaceCollection](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterfacecollection/) | Represents a collection of [OpcClassicInterface](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterface/) instances keyed by their [Identifier](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterface/members#identifier). |
| [OpcClassicInterfaces](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicinterfaces/) | Provides the interface specifications of OPC Classic supported by the SDK. |
| [OpcClassicOrganization](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicorganization/) | Defines the type of namespace organization to use while browsing the address space. |
| [OpcClassicProxyCapabilities](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.classic.opcclassicproxycapabilities/) | Specifies various capabilities in CoInitializeSecurity and IClientSecurity::SetBlanket (or its helper function CoSetProxyBlanket). |