> For the complete documentation index, see [llms.txt](https://docs.marpledata.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.marpledata.com/docs/marple-db/datastreams/preprocessing-rules.md).

# Preprocessing rules

A datastream can be configured with preprocessing rules. These allow you to clean your data into a Unified Name Space (UNS).

<figure><img src="/files/khVwjXvhvyptxDSS3qrQ" alt=""><figcaption></figcaption></figure>

Per signal, you can configure

* **Output name**: a new name for the signal
* **Description**, will be added as signal metadata
* **Unit**
* **Gain and Offset**, applying the formula `new_value = input_value*gain + offset`

Additionally, you can choose the priority of a signal

* **High**: 1) the signal will be imported first when importing a file, and 2) the signal will also be loaded into hot storage automatically
* **Default**: no special treatment

### Discover Preprocessing in 1 minute

{% embed url="<https://www.youtube.com/watch?index=25&list=PLtVuqpI9QpJAFtUEvuS23Z47XGHrRc_P9&v=Rs5SABXH2pw>" %}

Want to discover more Marple features in 1 minute? Check out other [1 Minute Marple videos](/docs/other-resources/1-minute-marple-videos.md)