A valid reason for keeping a customer transaction beyond the retention schedule is a pending legal hold. A legal hold is a requirement or an order to preserve certain records or data that are relevant or potentially relevant to a legal matter, such as a lawsuit, an investigation, or an audit. A legal hold can override the normal record retention schedule or policy of an organization, and can mandate the organization to retain the records or data until the legal matter is resolved or the legal hold is lifted. A pending legal hold can be a valid reason for keeping a customer transaction beyond the retention schedule, as it can ensure the compliance, evidence, or liability of the organization or the customer. Long term data mining needs, customer makes request to retain, and useful for future business initiatives are not valid reasons for keeping a customer transaction beyond the retention schedule, as they are related to the business value, preference, or strategy of the organization or the customer, not the legal obligation or necessity of the organization or the customer. References: CISSP All-in-One Exam Guide, Eighth Edition, Chapter 1, Security and Risk Management, page 49. Official (ISC)2 CISSP CBK Reference, Fifth Edition, Chapter 1, Security and Risk Management, page 64.