> ## Documentation Index
> Fetch the complete documentation index at: https://docs.railmail.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Topics

> The consent layer: topics define what a subscriber agrees to receive.

A **topic** is a subscription category your subscribers see and control in their [preference center](/en/guide/preference-center), for example *Weekly newsletter*, *Product updates* or *Promotions*. Topics are the **consent layer**: they define **what** a subscriber agrees to receive. Every campaign is sent to a topic.

## Create a topic

In **Topics**, click **Add topic**:

| Field              | Notes                                                                  |
| ------------------ | ---------------------------------------------------------------------- |
| Name               | Visible to the subscriber in the preference center (3-100 characters). |
| Description        | What the subscriber will receive (up to 500 characters).               |
| Expected frequency | For example, *1×/week*.                                                |
| Double opt-in      | Toggle between **double opt-in** and **single opt-in**.                |

## Double opt-in

With **double opt-in**, a subscriber must confirm before they count as subscribed:

<Steps>
  <Step title="Consent is requested">
    When someone subscribes, Railmail sends a confirmation email. Their consent status is **Pending confirmation**.
  </Step>

  <Step title="They confirm">
    After they click the link, the status becomes **Confirmed** and they start receiving that topic's email.
  </Step>

  <Step title="If they don't confirm">
    You can **resend the confirmation**. A confirmation can also **expire** if left unconfirmed.
  </Step>
</Steps>

Double opt-in protects your deliverability and keeps you compliant. Use single opt-in only when you already hold valid consent.

## Topic properties

Open a topic to manage:

* **Status**: Active, Draft, Inactive or Archived.
* **Priority**: Urgent, High, Medium, Low or No priority. Helps you order topics.
* **Double opt-in**: on or off.
* **Consent expiry**: whether consent expires after a period.
* **Frequency** and **active subscribers**.

Use the change dialogs to update priority, status or double opt-in at any time.

## Topic actions

From the topic list or detail view you can **Activate**, **Set as draft**, **Deactivate**, **Archive** or **Delete** a topic. The **Subscribers** tab shows everyone subscribed to that topic and their consent state.

<Note>
  Topics answer **what**; [segments](/en/guide/segments) answer **who**. A campaign sends to a topic, optionally narrowed by a segment.
</Note>