The Validation and Transformation Language (VTL) is a standard language for defining validation and transformation rules (set of operators, their syntax and semantics) for any kind of statistical data. VTL builds on the SDMX information model, but it can also be used with any kind of structured data and data typology (microdata, aggregated data, registers, qualitative, quantitative).
The logical formalisation of VTL validation and transformation rules allows several implementations using specific programming languages for execution (R, SAS, Java, SQL etc.).
The VTL specifications have been developed under the umbrella of the SDMX community. They will form the basis for ESS shared tools/service developments and will be used as a common language for documenting ESS validation rules.
More details on VTL.