# How does whitelisting work?

Whitelisting requires two things:

1. Activating the [Delta Screening](https://developer.screena.ai/#about-delta-screening) option when creating a new [API key](https://developer.screena.ai/#authentication).
2. All entities sent for screening should be associated with a `dataID` to track the results when performing a search on any entity sent to the API. If there are any hits, the system takes note of this, and will not return the same results for subsequent searches on that entity, unless the contents of those results change as well.

{% hint style="info" %}
To set up Delta Screening for your Screena Firm subscription, contact <experts@screena.ai>
{% endhint %}

{% hint style="info" %}
It is possible to control and turn off Delta Screening per request using the parameter `lastMatch` which shall be set at `false`.
{% endhint %}