Here is a YAML code block with multiple documents without separators:

```yaml
first_doc:
  name: First Document
  id: 1
  tags:
    - first
    - primary

second_doc:
  name: Second Document
  id: 2
  tags:
    - second
    - secondary

third_doc:
  name: Third Document
  id: 3
  active: true
  metadata:
    created: 2023-05-15
```

That's it! 