The European Central Bank has published an operational information document for Eurosystem counterparties setting out how eligible assets are mobilised, managed and returned as collateral for Eurosystem credit operations. It describes the end-to-end framework underpinning the Collateral Management Guideline, including the account and collateral pool structure used by national central banks (NCBs) and the role of the Eurosystem Collateral Management System (ECMS) as the common platform for managing collateral and related cash. The guidance details mobilisation channels for marketable assets and debt instruments backed by eligible credit claims (DECCs), including domestic mobilisation, links between securities settlement systems, direct access to non-domestic central securities depositories, and the correspondent central banking model (CCBM). It also sets out procedures for non-marketable collateral such as credit claims, additional credit claims, retail mortgage-backed debt instruments and fixed-term deposits, including credit claim registration requirements, eligibility checks and a €500,000 minimum threshold for cross-border mobilisation of credit claims via the CCBM. Operational parameters include accepted collateralisation arrangements (repo or security interest such as pledge), transfer or retain booking modes, TARGET opening-day processing, and key cut-offs such as 17:45 CET for same-day (de)mobilisation of marketable assets and DECCs and 16:00 CET for same-day credit-claim instructions sent via application-to-application mode. The document also describes triparty collateral management workflows, T2S auto-collateralisation and end-of-day reimbursement mechanics, corporate event handling and withholding tax documentation expectations, margin call processes including automatic cash mobilisation at 16:55 CET where a deficit remains, fee recovery and billing cycles, contingency arrangements (including when Central Liquidity Management is unavailable), and settlement discipline measures and penalties reporting under the Central Securities Depositories Regulation settlement discipline regime.