# Points to remember

#### Message Communication and Handling

**REST Connectivity**:

* **Authentication**: Authentication is passed using basic authorization in REST connectivity.
  * If the credentials are found invalid, an error response needs to be returned.

**POS Source Element**:

* The `POS` source element contains `<CompanyName Code="BKNG"/>`, referring to the OTA/Channel code mapped in RateGain's Channel Manager system.
* For a complete list of OTA/Channel codes supported, please contact the RateGain team.

**Comments Handling**:

* Comments can be added either per room or globally for a reservation.
  * **Global Comments**: If any comment applies to the whole booking, it should be included in `ResGlobalInfo`.
  * **Room-specific Comments**: If a comment is required for a specific room, add it to the `RoomStay` section.

**Reservations Without Credit Card Details**:

* For reservations booked without credit card details, the `<Guarantee>` element may or may not be present in `ResGlobalInfo`.
  * If present, it should specify `GuaranteeCode` and `GuaranteeType` as follows:

\<Guarantee GuaranteeType="None" GuaranteeCode="NOT GUARANTEED"/>