ARI Sync - Availability (OTA) SOAP API 10.21 The ARI Sync- Availability (OTA) (OTA_HotelBookingRuleNotifRQ) is used to limit the availability for a hotel. The ARI Sync- Availability (OTA) (OTA_HotelBookingRuleNotifRQ) is used to limit the availability for a hotel. Property Connect Open Travel Alliance Availability Stay Restrictions PMS Integration