Health Level Seven (HL7) has evolved into an international standards development organization (SDO) with a suite of standards. Prominent among these are formalisms related to clinical decision support, including the Arden Syntax, GELLO and Decision Support Service (DSS) standards. Continuing improvement in these standards and ongoing development of future decision support standards require wide participation in order to maximize their success. Accordingly, the purpose of the workshop is twofold. First, instructors will convey the latest developments regarding existing decision support standards and related efforts to develop new standards. Second, the instructors will solicit feedback so that attendees who do not participate in HL7 can have input into the standards activities of that organization. The instructors of this workshop, who are the co-chairs and/or members of the Clinical Decision Support Technical Committee of HL7, will review progress in these areas. They will present the details of the ongoing development of the extant Arden Syntax, GELLO and DSS standards. They will discuss work on current draft and proposed future standards, including the Infobutton communication and Order Set standards that are undergoing development in anticipation of certification as standards. Finally, they will solicit discussion regarding the future direction of standards development in these areas.