title: _id
---
summary: The local identifier of a record.
---
type: sysfield
---
body:

Each record has an `_id`.  This ID is basically a form of the filename.
Depending on if you are looking at an attachment or a page the rules are
slightly different.

For pages the ID is the name of the folder.  So if you have a page called
`docs/overview/contents.lr` then `_id` is `overview`.  If you have however
an attachment named `docs/overview/screenshot.jpg` the `_id` will be the
filename of the attachment: `screenshot.jpg`.

Note that IDs are not globally unique!  There is also the `_path` which is
the entire path of the record.

The `_id` is automatically set and cannot be overridden.

## Example

```html+jinja
<ul class="nav">
{% for item in site.query('/projects') %}
  <li{% if item._id == this._id %} class="active"{%
    endif %}>{{ item.name }}</li>
{% endfor %}
</ul>
```
