MISMO Engineering Guidelines 0025 (Extending a Standard MISMO XML Schema) V2.0
MEG 0025 was approved as final in September of 2025.
Updates to this MEG include:
- Updated section 25.8 with additional guidance for implementing enumerated values
MEG 0025 provides guidance on how to extend the MISMO Version 3.x XML schema. That is, the architecture provides an orderly way of “extending” a MISMO schema—enabling a message to hold additional data needed for mortgage processing that is not included in a specific MISMO XML schema version. The goals of the MISMO Extension Model are as follows:
- Allow any container element to be extended (added on to);
- Identify and separate MISMO data and extended data;
- Allow extensions from multiple organizations to coexist in a single XML instance including within the same container;
- Allow simultaneous schema validation of MISMO and OTHER content.
Additional details are provided in the MEG for handling EXTENSION containers and attributes.
Access Information for Members
MISMO Members can access MEG 0025 within the Resource Library housed on MISMO's Collaboration Site, "MISMO Connect" here.
Access Information for Non-Members
Non-MISMO members can access MEG 0025 here.