Syntax validation in SWIFT MT type trees

The syntactic definition covers the following elements:

• Blocks 1, 2, 3, and 5 - envelope validation:
  • Check the block structure.
  • Ensure that only permitted fields are present, and in the correct order.
• Block 4 - message body validation:
  • Make certain that only permitted sequences and fields are present.
  • Check the sequence structure and the order of sequences.
  • Check the order of fields within the message or within the sequence.
  • Check for the allowed format options of a field (for example, 98A and 98C).
  • Check the structure of sub-fields with a field.
  • Check for valid qualifiers of a field.
  • Check the cardinality of qualifiers, fields, and sequences (that is, optional, mandatory, repeating).
• Data size
  • For each field, or subfield, check the minimum and maximum size restrictions.
• Data type
  • For each field, or subfield, check data type (date, integer, decimal, text). For text fields, character set validation is not performed.
• Code words
  • For each field, or subfield, check for a valid code word. Code words are only validated when an error code is quoted in the SWIFT User Handbook.