The latest version of the Health Level Seven (HL7) Arden Syntax for Medical Logic Systems was approved by the American National Standards Institute (ANSI). Amongst other improvements, the version’s new feature ArdenML, an XML representation of Arden Syntax’s medical logic modules (MLMs), allows the Arden Synax to be compatible with all other HL7 standards based on XML (HL7 version 3, VmR, and others).