# IJournalFormat Properties

[Type overview](/orleans/docs/api/csharp/microsoft.orleans.journaling/orleans.journaling.ijournalformat/)

## FormatKey {#formatkey-6eb2fc38}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.journaling/orleans.journaling.ijournalformat/properties/formatkey-6eb2fc38/)

```csharp
public abstract string FormatKey
```

Gets the key which identifies this journal format in storage metadata and keyed service registration.

## MimeType {#mimetype-fdb9c871}

[Dedicated page](/orleans/docs/api/csharp/microsoft.orleans.journaling/orleans.journaling.ijournalformat/properties/mimetype-fdb9c871/)

```csharp
public abstract string? MimeType
```

Gets the MIME type for journal storage written with this format, or `null` to use the storage provider's default.