Ryan:
The QR code decoder supports structured append via the SD_PROP_RESULT_QR_POSITION and SD_PROP_RESULT_QR_LAST properties which provide the index and total number of QR Codes involved in a structured append. In Aztec, the result modifer is set to a value between 6 and 11 to indicate a structured append header is contained in the Aztec code being issued as defined in the AIM Symbology Identifier standard. The first two characters of the issued decode then indicate the index and total number of symbols involved in the structured append (A == 1, B == 2, ...) respectively. Thus all the info to recreate the structured append (as well as confirmation that a structured append header is in the symbol) is available. In the QR code case, the structured append data did not appear in the decoded output so we had to add additional properties to get the information to the user. Normally we only add extra properties when the information is not available in the normal output stream and/or symbology modifier.
Bob