# Sign

Every change of the system state must be confirmed with a user signature. A change can be e.g., a user email change, measuring point calibration adjustment or alarm acceptance.

History of all the changes is stored in database for further reference.

When signing is needed, a “User Signature” form is opened.

![](https://3107031480-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPTZRr97g6y1opAswEdao%2Fuploads%2Fgit-blob-d75d6f67dc73f696e3b80c19583ed41a4713e284%2Fimage18.png?alt=media)

If PIN is enabled in the system group and for the user then the sign form looks as below:

<figure><img src="https://3107031480-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPTZRr97g6y1opAswEdao%2Fuploads%2FDsDvRX52dcueZXBRraxw%2Fimage.png?alt=media&#x26;token=f8350c7f-d7f6-4c27-89d5-663413562103" alt="" width="458"><figcaption></figcaption></figure>

To sign:

1. Enter your username and password or PIN.
2. It is good practice to enter a comment that explains the reason for a change. It is possible to make a comment mandatory for a System Group as described in [settings\_\_system\_group\_settings](https://help.boomerang3.com/boomerang-3-domain-administrator-manual/admin/settings/settings__system_group_settings "mention").
3. Click “Sign” button.
4. The system shall confirm the change has been done.

![](https://3107031480-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPTZRr97g6y1opAswEdao%2Fuploads%2Fgit-blob-c39c56f23910b098dbb3f675793855be1053554d%2Fimage19.png?alt=media)