FIXML Schema Files now created from Orchestra

The FIX Global Technical Committee (GTC) has completed the transition of the FIXML schema files for FIX Latest from the Basic repository to the Orchestra repository. This change is effective as of EP277.

FIXML is the XML encoding used within FIX. FIXML is widely adopted for derivatives post trade clearing and settlement globally. Orchestra is the standard for machine readable Rules of Engagement and was developed by FIX. It is used for the third generation of XML representations of the FIX Protocol. The first generation was the Basic repository followed by the Unified repository. The XML representations are used by the GTC to generate artifacts such as FIXimate and the FIXML schema files.

The Orchestra Technical Standard was developed to significantly enhance the representation of meta-data for FIX and non-FIX electronic interfaces. Version 1.0 was published in February 2021 and has been used to provide an additional XML representation of FIX Latest since EP255. Currently, FIX Latest is still provided in all three repository formats (Basic, Unified, Orchestra).

The GTC has now completed the generation of all artifacts to the Orchestra repository. The Basic repository is no longer needed to generate the FIXML schema files and will eventually be discontinued.

The following sections describe the differences between the FIXML schema files created from Basic compared to Orchestra in detail.

Component Types

Components in the Basic repository have different types of components, identified with the element <ComponentType>. The component types, “ImplicitBlock” and “ImplicitBlockRepeating” had been used for the FIX Specification to identify (repeating) blocks embedded inside the message layout table. The need to make such a distinction was no longer needed as of FIX 5.0 but had not been removed from the Basic repository. The Orchestra repository no longer has component types. Blocks are distinguished from repeating blocks by being part of <fixr:components> or <fixr:groups> respectively.  The FIXML schema files created from the Orchestra repository continue to provide the component types “Block” and “BlockRepeating”. The component types “ImplicitBlock” and “ImplicitBlockRepeating” have been changed to “Block” and “BlockRepeating” respectively.

Namespaces

The new FIXML Schema files have an additional namespace for Orchestra:

xmlns:fixr="http://fixprotocol.io/2020/orchestra/repository

References to the legacy FIX Protocol specification

The new FIXML Schema files no longer contain references to Volumes 3-5 of the legacy FIX Protocol specification as that has been replaced with the new (online) version. This change only affects the <xs:documentation> elements inside the FIXML schema files.

Ordering of field values

XML elements do not have a specific sort order. This affects the file fixml-fields-base-Latest.xsd. In some cases, enumerations of fields in the new FIXML schema files are different in terms of the order they appear in. This affects the element <fm:EnumDoc> (inside element <xs:appinfo>) and the elements <xs:enumeration> or <xs:pattern> (inside element <xs:restriction>).

There are no differences regarding the individual values themselves and should hence have no impact on the validation of FIXML messages.