Enum describing the request type of a reservation booking.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/enums/reservation_request_type.proto)

| Enums ||
|---|---|
| ## `BOOK` | Book the campaign. The campaign must have ENABLED status. If the campaign has a hold, it will remove the hold and confirm the contract. |
| ## `HOLD` | Hold the inventory for the campaign. The campaign must have PAUSED status to request a hold. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |