# HTTP Header: Set interest-cohort empty

As it is written in this [page](https://developer.chrome.com/blog/floc/):

> A site should be able to declare that it does not want to be included in the user's list of sites for cohort calculation. A new interest-cohort permissions policy enables this. The policy will be allow by default.
> A site can opt out of all FLoC cohort calculation by sending the HTTP response header:

`Permissions-Policy: interest-cohort=()`

#### Apache

In `/etc/apache/apache2.conf`:

After the line of loading all enabled module (make sure `headers.load` is added in `/etc/apache2/mods-enabled`), and before the line of loading sites-enabled, add:

```apache
<IfModule mod_headers.c>
    Header set Permissions-Policy "interest-cohort=()"
</IfModule>
```

#### Nginx

Before the line of loading sites-enabled configure file:

In `/etc/nginx/nginx.conf`

```nginx
add_header Permissions-Policy "interest-cohort=()";
```

## Reference:

* https://developer.chrome.com/blog/floc/