SWIFT Trailers
Each SWIFT message has one or more trailers as required by the message exchange and security requirements. System trailers, if applicable, follow user trailers. Each trailer within the Trailer Block appears within a subblock delimited by further pairs of curly brackets. Each subblock begins with three letters denoting the trailer type, followed by a colon.
The SWIFT Trailer schema (SWIFT Trailer.xsd) contains the format for the following:
The ending delimiter of the text block
User trailers (user and system information)
System trailers
The ending delimiter of the Text Block is "-}". The trailer block begins with "{5:". The contents of the trailer block include both user information (checksum, message authentication, proprietary authentication, and so on), and system information (delayed message, message reference, possible duplicate message, and so on). Trailers added by SWIFT also provide a third block, delimited by "{S:". The SWIFT User Handbook, "FIN Service Description" topic, describes in detail the contents of block 5. A4SWIFT does not validate the contents of block S.
The actual FIN interface or the SWIFT network appends the trailers. If a message contains a trailer when A4SWIFT receives the message, A4SWIFT carries the trailer with the message. A4SWIFT does not raise an error if a message does not contain a trailer when A4SWIFT receives the message. As with headers, all of the trailer entries, including the blocks themselves, are optional in A4SWIFT.
This section contains: