---
title: Frontmatter
description: Every Markdown file referenced in the TOC may optionally define a frontmatter block. Frontmatter is YAML-formatted metadata about a page, at the beginning...
url: https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/3805/syntax/frontmatter
products:
  - Elastic Docs Builder
---

# Frontmatter
Every Markdown file referenced in the TOC may optionally define a frontmatter block.
Frontmatter is YAML-formatted metadata about a page, at the beginning of each file
and wrapped by `---` lines.
In the frontmatter block, you can define the following fields:
```yaml
---
navigation_title: This is the navigation title. 
description: This is a description of the page. 
applies_to: 
  serverless: all
products: 
  - id: apm-agent
  - id: edot-sdk
sub: 
  key: value 
cta: 
  id: beta
---
```


## Navigation Title

See [Page title](https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/3805/syntax/titles)

## Description

Use the `description` frontmatter to set the description meta tag for a page.
This helps search engines and social media.
It also sets the `og:description` and `twitter:description` meta tags.
The `description` frontmatter is a string, recommended to be around 150 characters. If you don't set a `description`,
it will be generated from the first few paragraphs of the page until it reaches 150 characters.

## Applies to

See [Applies to](https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/3805/syntax/applies)

## Products

The products frontmatter is a list of products that the page relates to.
This is used for the "Products" filter in the Search UI.
The products frontmatter is a list of objects, each object has an `id` field.
Only products with the `public-reference` feature enabled in [`products.yml`](https://github.com/elastic/docs-builder/blob/main/config/products.yml) are valid here. Products that have set `public-reference: false` cannot be used in frontmatter.

| Product ID                     | Product Name                              |
|--------------------------------|-------------------------------------------|
| `apm`                          | APM                                       |
| `apm-agent`                    | APM Agent                                 |
| `auditbeat`                    | Auditbeat                                 |
| `beats`                        | Beats                                     |
| `cloud-control-ecctl`          | Elastic Cloud Control ECCTL               |
| `cloud-enterprise`             | Elastic Cloud Enterprise                  |
| `cloud-hosted`                 | Elastic Cloud Hosted                      |
| `cloud-kubernetes`             | Elastic Cloud Kubernetes                  |
| `cloud-serverless`             | Elastic Cloud Serverless                  |
| `cloud-terraform`              | Elastic Cloud Terraform                   |
| `ecs`                          | Elastic Common Schema (ECS)               |
| `ecs-logging`                  | ECS Logging                               |
| `edot-cf`                      | Elastic Cloud Forwarder                   |
| `edot-sdk`                     | Elastic Distribution of OpenTelemetry SDK |
| `edot-collector`               | Elastic Agent                             |
| `elastic-agent`                | Elastic Agent                             |
| `elastic-serverless-forwarder` | Elastic Serverless Forwarder              |
| `elastic-stack`                | Elastic Stack                             |
| `elasticsearch`                | Elasticsearch                             |
| `elasticsearch-client`         | Elasticsearch Client                      |
| `filebeat`                     | Filebeat                                  |
| `fleet`                        | Fleet                                     |
| `heartbeat`                    | Heartbeat                                 |
| `integrations`                 | Integrations                              |
| `kibana`                       | Kibana                                    |
| `logstash`                     | Logstash                                  |
| `machine-learning`             | Machine Learning                          |
| `metricbeat`                   | Metricbeat                                |
| `observability`                | Elastic Observability                     |
| `packetbeat`                   | Packetbeat                                |
| `painless`                     | Painless                                  |
| `search-ui`                    | Search UI                                 |
| `security`                     | Elastic Security                          |
| `winlogbeat`                   | Winlogbeat                                |


## Subs

Use the `sub` field to define local substitutions. Refer to [Substitutions](https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/3805/syntax/substitutions) for more information.

## CTA

See [CTA](https://docs-v3-preview.elastic.dev/elastic/docs-builder/pull/3805/documentation/isolated/cta).