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Formal vs. Informal Help Informal Formal


Todd Cochrane


Advise whether a segment without elements is valid; and if segment is not valid, what syntax error codes should be resumed on the 997.


X12.6 Section 3.2 unequivocally states that the syntax is defined by the Backus Naur Form (BNF) constructs in X12.6. BNF notation is described in X12.6 Section 3.2.1 through 3.2.8. This section further states: In some cases actual use (the actual data stream) of an X12 structure may not be the same as the definition. These instances are caused by the optional nature of some structures. Where such structures occur in this document, two representations of the BNF are presented, labeled definition and use respectively. The BNF in X12.6 Section 3.7 Data Segment includes a use BNF representation. That representation requires the presence of a data_segment_unit , which in turn requires the presence of either a repeating_simple_data_element or a repeating_composite_data_structure . Each of these structures have separate use definitions within the use BNF of 3.7 Data Segment. The repeating_simple_data_element structure requires the presence of a simple_data_element . As there is no use BNF in 3.7 Data Segment for this structure, the BNF in 3.5 Data Element applies. That BNF requires the presence of a data_element . The repeating_composite_data_structure requires the presence of a composite_data_structure . As there is no use BNF in 3.7 Data Segment for this structure, the BNF in 3.6 Composite Data Structure applies. In that section, there is a use BNF for composite_data_structure , and that BNF requires the presence of a component_data_element . As there is no use BNF provided for component_data_element , the BNF in 3.5 Data Element applies. That BNF requires the presence of a data_element To summarize the above analysis, the segment terminator must be preceded by a data_element . Section 3.5 Data Element BNF defines data_element as a choice among several BNF constructs. Each of these constructs is defined in 3.5.1 Data Element Types, and each of these constructs requires the presence of at least one character. All of these types except binary and fixed_length_string further require the presence of a non-blank character. ADVICE Non-Normative Advice on Reporting Error on invalid segment usage. It is recommended that segment AK3 be used to identify the segment in error, and that DE 720 report the error as Segment Has Data Element Errors (code 8). It is acceptable to further report, in segment AK4, Conditional required data element missing , since the segment use BNF establishes an implied condition that at least one of the elements comprising the segment must be present.


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Submission 1/1/2003
Status Date 1/1/2003
Status F - Final
Primary References
Document 4010 X096