# Topics (interests)

> A topic in MailCamp is an interest category that a contact manages themselves. Topics split one audience into interest groups — subscribers sign up once, then choose which subjects they actually want to receive, and they keep that choice under their own control.

## What it is

A topic is a subscriber-facing preference. Where a segment is a filter you apply and a tag is a label you assign, a topic is something the recipient picks: on a subscribe form at signup, or later on an unsubscribe form or preference page. Because the contact opted in explicitly, a campaign targeted at a topic carries that consent with it.

Topics are the main reason an account no longer needs a separate mailing list per subject. Instead of a "Newsletter" list and a "Product news" list, there is one audience with two topics.

## Key concepts

- **Topic**: a name, nothing more. The name is shown to subscribers, so it should be self-explanatory ("Monthly newsletter", "Product news").
- **Link to a list**: a topic only appears for subscribers of the mailing lists it is linked to. Linking happens in the list's (audience) settings.
- **On forms**: subscribe forms can show the topics of their list so new contacts choose at signup. Unsubscribe forms show them above the unsubscribe reasons, so a recipient can drop one subject instead of leaving entirely.
- **On a contact**: the topics field appears on a contact only when its list has topics linked.
- **In segments**: `has topic = X` is a segment rule and can be combined with tag and field rules.
- **At import**: a topic can be attached during a CSV import, so imported contacts start in the right interest group. They can change it themselves afterwards.

## Topics versus tags

Both group contacts, but the difference is who controls the grouping:

- A **tag** is set by you, the sender. The contact never sees it. Use it for internal grouping.
- A **topic** is a preference the contact sees and manages. It carries their implicit consent, which is what makes topic-targeted sending legitimate.

Both are valid segment rules, and they combine — for example `tag = customer AND topic = product-news`.

## Common workflows

### Creating a topic

1. Open **Contacts → Topics**.
2. Choose **Create a new topic** and give it a subscriber-facing name.
3. Link it to one or more mailing lists from the list (audience) settings.
4. Expose it on the subscribe and unsubscribe forms of that list.
5. Target it from a segment when building a campaign.

### Letting a recipient keep part of their subscription

When a recipient clicks the unsubscribe link and the list has topics, the unsubscribe form lists those topics above the unsubscribe reasons. The recipient can untick the weekly mailing and keep the monthly one instead of leaving completely.

## Limits and edge cases

- A topic that is still linked to a mailing list cannot be deleted — unlink it first.
- Deleting a topic also removes that interest from every subscriber who had it.
- Renaming a topic changes it everywhere it is shown, including on forms already published.
- Topics belong to the list they are linked to; a contact on another list does not see them.

## Web routes

- `/contacts/lists/topics` — topic overview.
- `/contacts/lists/topics/new` — create a topic.
- `/contacts/lists/topics/:id/update` — rename a topic.

## Related

- [Tags](/llms/tags.txt) — the sender-controlled counterpart.
- [Mailing lists](/llms/mailing-lists.txt) — where topics are linked.
- [Forms](/llms/forms.txt) — where subscribers pick topics.
- [Segments](/llms/segments.txt) — targeting a topic in a campaign.