# Selector Atoms

Atoms are the building blocks of selector expressions. Each atom matches documents based on a single criterion.

## Tag

Matches documents that have a specific tag.

```
#engineering
tag:#engineering      # same thing
```

## Type

Matches documents by their `type` frontmatter field.

```
type:document
type:source
type:reference
```

## Status

Matches documents by their `status` field.

```
status:published
status:draft
```

## Pack

Matches all documents included in a named context pack.

```
pack:engineering-essentials
```

## Title

Matches a single document by its title.

```
[[API Design Guide]]
```

## Scope

Matches documents in a visibility scope.

```
scope:team
```

## Node id

Matches a single document by its node id (or its `contextnest://` URI).

```
nodes/architecture-overview
contextnest://nodes/architecture-overview
```

## Not supported

There is no `path:` glob atom. To select a group of documents by location, tag them or put them in a pack. `transport:` and `server:` describe how a source node connects. They are not query atoms.