---
title: "Classifications"
description: ""
url: "https://docs.itrsgroup.com/docs/itrs-analytics/app/entities/1.22.0/user-guide/classifications/index.html"
---
Entities in ITRS Analytics are identified by their unique set of dimensions. However, different data sources may use different conventions for assigning dimensions. This means that entities that are similar conceptually may have very different dimensions and be difficult to capture in one query.

Consider the following two entities as an example:

- Geneos data: ```[probe=CENTOS7-MLG5, managedEntity=CENTOS7-MLG5, type=All, sampler=Disk, dataview=Disk, row=/boot]```
- Collection Agent plugin data: ```[hostname, device, volume]```

Both entities represent disks, but have very different dimensions.

To resolve this problem you can create policies that assign special attributes to entities called ```classifications```. You can then use classifications to easily create simple queries.

The Classifications page shows all current policies used to assign classification attributes.

![Classifications](https://docscdn.itrsgroup.com/itrs-analytics-app-entities/images/classifications-1-17-0.png)

## Create a new classification policy

To create a new policy that assigns classifications:

1. Click **Edit** to enter  editing mode.
2. Click the **Add rule** button.
3. Specify an **Attribute Name**. This is the attribute that attached to all entities this policy effects.
4. Specify one or more policy rules. You must specify an **Attribute Value** and a pattern that defines **Where** each policy rule is applied. To do this use an [Expression](https://docs.itrsgroup.com/docs/itrs-analytics/platform/current/getting-started/query-lang/).
5. (optional) If you have set multiple policy rules you can order them using the arrow buttons.
6. Click **OK**, then click **Save**.

## Edit a classification policy

To update an existing classification policy:

1. Click **Edit** to enter editing mode.
2. Select the menu button of the policy you want to change, then click **Edit**.
3. Modify the **Attribute Name**.
4. Add or modify policy rules. If you have set multiple policy rules you can order them using the arrow buttons or delete them using the delete button.
5. Click **OK**, then click **Save**.