# IMSC, TTML, and WebVTT (sidecar) output captions
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 This section covers how to configure IMSC, TTML, and WebVTT (sidecar) output captions in AWS Elemental MediaConvert. The main topics include:
+ Where to specify the captions.
+ How to specify multiple captions tracks.
+ Sidecar captions container options.

If your output captions are IMSC, TTML or WebVTT format, set them up in your outputs according to the following information. For restrictions on IMSC support, see [IMSC requirements](imsc-captions-support.md).

## Where to specify the captions
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Put your captions in the same output group, but a different output from your video.

After you add captions to an output, delete the **Video** and **Audio 1** groups of settings that the service automatically created with the output.

**To delete the Video and Audio 1 groups of settings**

1. On the **Create job** page, in the **Job** pane on the left, under **Output groups**, choose the output that contains the groups of settings that you want to delete.

1. The **Video** group of settings is automatically displayed in the **Stream settings** section. Choose the **Remove video selector** button.

1. The **Audio 1** group of settings is automatically displayed in the **Stream settings** section. Choose the **Remove** button.

## How to specify multiple captions tracks
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Put each captions track in its own output.

**Note**  
The captions track that you specify first in your job is signaled as the default track in the HLS manifest.

## Sidecar captions container options
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Depending on your output group, you can choose the captions container for IMSC and TTML captions outputs.

For **DASH ISO** output groups, you can choose from these:
+ Fragmented MP4 (`.fmp4`)
+ Raw (`.xml` for IMSC, `.ttml` for TTML)

For all other output groups, IMSC and TTML files are raw.

**To specify the captions container for IMSC and TTML captions in DASH ISO output groups**

1. Set up the outputs in your **DASH ISO** output group as described in [Creating outputs in ABR streaming output groups](setting-up-a-job.md#create-outputs-in-abr-streaming-output-groups). Put captions in a separate output.

1. On the **Create job** page, in the **Job** pane on the left, choose the captions output.

1. In the **Output settings** section on the right, choose **Container settings**, and then enable **DASH container settings**.

1. For **Captions container**, keep the default **Raw** or choose **Fragmented MPEG-4**.