...
The Goessner notation for XML to JSON mapping and vice versa has been adopted by SIF in version 3.1. It provides a generic and loss-less mapping between the two formats. The Goessner mapping rules do not require and any XML schema knowledge or awareness. It can be performed by simply parsing the XML and applying the rules to produce the JSON and reverse. The mapping rules can be found on the XML.com page in the “Converting Between XML and JSON” section.
PESC
SIF 3.3 introduced adopted an additional XM/JSON mapping. These mappings have been developed by the Postsecondary Electronic Standards Council (PESC) with support of the A4L community and are referred to as PESC JSON. This XML/JSON mapping is a “schema-aware” mapping meaning that the XML Schema is taken into account when a translation between the two formats is performed. That approach resolves a couple of inconsistencies and drawbacks the Goessner notation encountered. The mapping rules can be found here.