# OpcAccessControlMode Enum

> Reference: Specifies how an OpcAccessControlEntry evaluates an operation which has neither been allowed nor denied explicitly and an endpoint which has neither been enabled nor disabled explicitly.

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx.server">Opc.UaFx.Server</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
</dl>

Specifies how an [OpcAccessControlEntry](https://www.traeger.de/en/docs/development/opcua/api/v2.59/opc.uafx.server.opcaccesscontrolentry/) evaluates an operation which has neither been allowed nor denied explicitly and an endpoint which has neither been enabled nor disabled explicitly.

## Syntax

<div class="api-signature" data-lang="csharp">

```csharp
public enum OpcAccessControlMode
```

</div>

<div class="api-signature" data-lang="vbnet">

```vbnet
Public Enum OpcAccessControlMode
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [ValueType](https://learn.microsoft.com/dotnet/api/system.valuetype) → [Enum](https://learn.microsoft.com/dotnet/api/system.enum) → **OpcAccessControlMode**

## Fields

| Name | Value | Description |
|---|---|---|
| <a id="blacklist"></a>`Blacklist` | `1` | An operation which has not been allowed explicitly is denied and an endpoint which has not been enabled explicitly is disabled. |
| <a id="explicit"></a>`Explicit` | `0` | An operation is allowed or denied and an endpoint is enabled or disabled only if this has been specified explicitly; otherwise the operation is neither allowed nor denied and the endpoint is neither enabled nor disabled. |
| <a id="whitelist"></a>`Whitelist` | `2` | An operation which has not been denied explicitly is allowed and an endpoint which has not been disabled explicitly is enabled. |

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.5–v2.59 |