# RegexImplicitChannelSubscriptionAttribute Constructors

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.broadcastchannel/orleans.regeximplicitchannelsubscriptionattribute/)

## RegexImplicitChannelSubscriptionAttribute(string) {#constructor-string-383c688c}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.broadcastchannel/orleans.regeximplicitchannelsubscriptionattribute/constructors/constructor-string-383c688c/)

[Source](https://github.com/dotnet/orleans/blob/e4e752cedecc2976811db49802c7a999b1f1c704/src/Orleans.BroadcastChannel/SubscriberTable/Predicates/ImplicitChannelSubscriptionAttribute.cs#L116-L118)

```csharp
public RegexImplicitChannelSubscriptionAttribute(string pattern)
```

Allows to pass a regular expression to filter stream namespaces to subscribe to.

### Parameters

- `pattern` (`string`): The stream namespace regular expression filter.