This publication provides an overview of central securities depository and real-time gross settlement linkages in the ASEAN+3 region. It was prepared for the Cross-Border Settlement Infrastructure Forum (CSIF) to support its efforts to establish central securities depository and real-time gross settlement linkages. It aims to build a common understanding among CSIF members about international standards and gateways for these linkages, including user requirements and technical specifications. The publication reflects the collaborative efforts currently underway to further harmonize and integrate bond markets among the ASEAN+3 economies.