Some data elements are outlined in Bold to reflect mandatory usage but are also labeled as optional or Situational. How do i interpret that? Where is the rule that allows me to understand that? Pg 70 - ST03 is outlined in bold but has a req designator of O for optional. Can you help me understand this?
The standard establishes all the segments and data elements for all transactions, and each implementation guide is composed of segments and data elements from the standard that best convey the information that needs to be communicated in that particular EDI transaction set.
The standard designates whether segments or data elements are mandatory (M), optional (O), or relational (X). If a segment is mandatory it must be included in all transaction sets, but specific data elements within the segment may or may not be used by a transaction set. See section B.1.1.3.1 and specifically N.1.1.3.9 for additional information about the standards nomenclature. The implementation guide further defines the elements to say whether they are required (R), situational (S) or not used for that guide. See section B.1.1.3.12.6 for more information about the implementation nomenclature.
Your question specifically refers to the 000510X222 the 837 professional implementation. The X12 standard defines the ST segment as mandatory (M). Therefore, the 837P implementation must define the ST segment’s usage as required (R). It further defines the data elements within the segment as follows:
• ST01 is mandatory per the standard and required per the implementation
• ST02 is mandatory per the standard and required per the implementation
• ST03 is optional per the standard but required per the implementation.
An example where this is different, is in the 005010X221A1. In the 835 transaction implementation, the ST segment is mandatory per the standard, but the 03 data element is designated as “Not Used.”
Note:
This is the note from the 837 implementation guide to explain why it is required to send the ST03 for this transaction even though the standard designates it as optional.
This information is also in the GS08 This field contains the same value as GS08. Some translator products strip off the ISA and GS segments prior to application (ST-SE) processing. Providing the information from the GS08 at this level will ensure that the appropriate application mapping is used at translation time.