RMDSThis change request proposes the introduction of the latest version of the Harmonised Baseline (HBL), V2.3. The Baseline has been agreed to ensure consistent implementations of the Core Elements (Messages and Data Definitions and Codes) of the Retail Electricity Market design across the ROI and NI jurisdictions. This request is a container request only, that is, is summarises all of the approved MCRs that impact on the previous HBL version and presents the resulting, updated HBL product. It does not, in itself, bring forward any new proposed changes.