X12 syntax in a 271
X12 syntax represents a message as segments separated by a terminator, with data elements separated by an element separator and composite components separated by a component separator. The Stedi 005010 references provide a public field cross-reference. X279A1 defines the complete grammar.
Segments and elements
Section titled “Segments and elements”A segment starts with an identifier such as ST or EB. Its elements follow
in order, as in this short excerpt from single-eb.edi:
ST*271*0101*005010X279A1~EB*1**30**SILVER PPO~The * separates elements in this example, and ~ ends each segment. A
composite element contains component values separated by the component
separator. Repetition separators can represent repeated values where the
transaction permits them. Empty positions still preserve element order; the
example’s two adjacent separators after EB*1 show empty values.
Delimiters and control values
Section titled “Delimiters and control values”The interchange header supplies delimiter characters at defined positions for
that interchange. Read them from each ISA; partners can choose different
characters.
Control values identify and count containers: ISA13 pairs with IEA02,
GS06 with GE02, and ST02 with SE02. The paired values let a receiver
relate each trailer to its opening container.
These observations describe the public examples and Stedi’s ISA reference. Use the implementation and partner guides for situational rules and parser requirements.