Hello, FpML 5.3 is backward compatible with FpML 5.2 within a corresponding schema View (i.e. a new version of the schema should continue to validate old instance documents; in this case the 5.3 Confirmation View schema should validate instance documents created with 5.0, 5.1, and 5.2. Confirmation View) In addition, FpML 5 supports FORWARD compatibility within a corresponding schema View (i.e., an instance document created with a new version of the schema should be schema compatible with an old schema, as long as it uses no features that arent in the new schema; in this case, in the 5.2 Confirmation View schema should validate instance documents created with 5-3 Confirmation View if it uses only features available in the 5.2 schema. Note: – FpML 5.2 includes Confirmation and Reporting schema Views. In FpML 5.3, two additional schema views are added: Transparency (real-time price reporting) and Recordkeeping (non-public SDR reporting) – There are known errata in FpML 5-2 that were corrected in 5.3 with the following incompatible changes: 1. In FpML 5.3 (fpml-doc.xsd), within “DataDocument” complex type: 1.1. Removed “ProcessingIndicator.model”. Rationale: Clean up the model. Added in 5.2 for SDR reporting but unused. 1.2. Removed “priceNotation”. Rationale: it was added in 5.2 to support Dodd Frank reporting, which subsequently was removed from 5-2. In 5-3 “priceNotation” was moved to a different location to avoid confusion, never used it that way. In 5.3, “priceNotation” replaced by the “quote” structure in the public and “nonpublicExecutionReports” 2. In FpML 5.3 (fpml-com.xsd), within CommodityAmericanExercise complex type: 2.1. Added a new container “exercisePeriod” to group “commencementDate” and “expirationDate” elements together. Rationale: Added support for Commodity Option Strip. 3. In FpML 5.3 (fpml-business-events.xsd) within TradeNotionalChange: 3.1. Changed the type of the elements “outstandingNotionalAmount” and “changeInNotionalAmount” from “Money” to “NonNegativeMoney”. Rational: Corrected to resolve some confusion in the examples. 4. In FpML 5.3 (fpml-reporting.xsd) within “TerminatingEventsReport” and “PositionActivityReport” complex types: 4.1. Changed type of elements “fromDateTime” and “toDateTime” from “xsd:date” to “xsd:dateTime”. Rationale: bug correction. Regards, Irina Yermakova