# databases.<name>.masking

> Masking rules applied to database branches before they are attached (mandatory for special-category projects).

Masking rules applied to database branches before they are attached (mandatory for special-category projects).
Keys are `table.column` or `schema.table.column`. Values: `fake_name`, `fake_email`, `fake_phone`, `fake_address`,
`fake_postcode`, `hash`, `hash_email`, `redact`, `keep`, `shift_days(±N)`, `constant(text)`, or null to set NULL.

- **Type:** map of names to null or string
- **Since:** manifest v1

## Example

```yaml
databases:
  main:
    masking:
      clients.full_name: fake_name
      clients.nhs_number: null
      clients.date_of_birth: shift_days(±30)
      carers.email: hash_email
```

## See also

- [databases](/docs/manifest/databases/): all fields of `databases`
- [guv.yaml reference](/docs/manifest/)