In dealing in Bank Guarantees (Demand Guarantees) and Letters of Credit (Documentary Credits), one may hear the phrase ‘MT799’.
This is the SWIFT Message Type that Bank Guarantees can communicate authenticated free format messages securely. Inter-communicating banks may use this Message Type on their SWIFT systems to communicate various types of messages and offer pre-advice of intended transactions. This Message Type is free format, allowing the Operator to type freely various different messages connected with MT700 communications, i.e. Documentary Credits and Guarantees.
It is important not to get caught up in inter-bank jargon and would advise that this phrase is not used when discussing Bank Guarantees as it neither concerns the client nor the recipient. Its meaning is strictly inter-bank communication and nothing else.