> For the complete documentation index, see [llms.txt](https://v2.isomer.gov.sg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://v2.isomer.gov.sg/configurations/navigation-bar/navigation-bar-configuration.md).

# Configuration

![](/files/-MJZsPCAZx_wuhC2p9iD)

The navigation bar configuration file is `_data/navigation.yml` and has 2 elements to configure, `logo` and `links`:

* `logo`: the path to the logo that will be located at the left of the navigation bar, e.g. `/images/logo.svg`. The logo size is adjusted dynamically by the user's browser, but we recommend a logo resolution of 170x50 pixels.
* `links`: a list of items in the navigation bar. Each item requires a `title`, which is the label that is visible to users on the navigation bar. The URL of each item can be specified in one of four ways:
  * For items that consists only of pages in a [collection](https://app.gitbook.com/configuration/pages/leftnav/), you can use `collection`, specifying the collection name. The subitems and URLs will be automatically generated by Isomer.
  * For a [resource room](https://app.gitbook.com/configuration/resources/overview/), you can specify `resource_room: true`. The links to the resource room and categories will be automatically generated by Isomer.
  * For a single link without subitems, simply specify the `url`, e.g. `/category/page/` or `https://www.google.com`. Remember to include the `https://` or `http://` in front of the URL if the link is to another site/microsite.
  * For an item with custom subitems, specify the `url` which will be the URL the user is brought to if they click on the link on the navigation bar directly. On top of that, specify `sublinks`, and provide a list of sublinks following the third format above.

Sample configuration of a navigation bar in `_data/navigation.yml`:

```yaml
logo: /images/logo.svg

links:
  - title: Sample Collection
    collection: sample-collection
  - title: Resource Room
    resource_room: true
  - title: Single Page
    url: /some-page/
  - title: Custom Sublinks
    url: /some-page-a/
    sublinks:
      - title: Subitem 1
        url: /some-page-a/
      - title: Subitem 2
        url: /some-page-b/
      - title: External Subitem 3
        url: https://www.site.com/url/to/page/
```