The segment delimiter signals the start of a segment record.
The segment ID is a six-character segment identifier that follows the segment
delimiter and combines with the nesting level to identify an MDR segment.
The nesting level is a single digit number ranging from zero-to-nine that combines
with the segment ID to identify an MDR segment. For more information, see Nesting_Rules.
An element delimiter separates the nesting level from the segment ID.
The mandatory/optional flag is a one-character field with the value of either
"M" or "O" (mandatory or optional). A mandatory segment must appear at
least once in a message. Nested mandatory segments must appear at least once under their
parent segment. An optional segment may appear within an SDS message, but it is not
required. An element delimiter separates the nesting level from the mandatory/optional
The repeat factor is a one-to-three-digit field that indicates the number of times
a segment may appear in a message. The minimum value for this field is one and the maximum
is 999. The value 999 in this field acts as an infinite repeat factor.
The segment delimiter terminates the segment record. This allows insertion of the
new fields in the segment record and still allows processing by older software.
The element record describes the properties of an element within a segment.
||(four-digit, base-36 number)
The element ID is a four-digit, base-36 number. A base-36 number is a number whose
digits range from 0-9, A-Z. Each element identifier uniquely defines a certain element
such as flight number, number in party, etc. The data elements and their definitions are
available from the application representative. An element delimiter follows the element ID