# Using blacklist

{% hint style="danger" %}
**This is for advanced use only**
{% endhint %}

The blacklist identifies the information that will not be retrieved when a PC is inventoried or when users are synchronised.

It is possible to prohibit a certain amount of information, such as IP addresses in 0.0.0.0 or a user with an @yopmail.com email address.

{% hint style="success" %}
You can blacklist the following items:

* IP
* MAC
* Serial number
* UUID
* Email (for users)
* Model
* Manufacturer
* Manufacturer
  {% endhint %}

## Add a new blaclist

For our example, we will block IPv6 forwarding

* To configure a blacklist, go to **`Setup`** > **`Dropdowns`** > **`Blacklists`**
* Click on **`+ADD`**
* Name your new blacklist
* Indicate the value (**`::1`** for IPv6)
* Select the expected value (IP for our example)

<figure><img src="/files/I2eqD5vghAfInWR5DEKP" alt=""><figcaption><p>View of blacklist</p></figcaption></figure>

## Delete a Blacklist

* To delete a blacklist, click on **`Delete permanently`**

<figure><img src="/files/mwYG7UBtOfMAE5k4jD0S" alt=""><figcaption><p>Delete a blacklist</p></figcaption></figure>

* You can use massive action to delete one or more blaclists

<figure><img src="/files/fB5cRXutC2eUJQm4Xpcr" alt=""><figcaption></figcaption></figure>


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.glpi-project.org/tutorials/inventory/advanced-usage/using-blacklist.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.