Configuring rule sets is the first activity that should be completed during the implementation of a DLP solution, because rule sets define the criteria and actions for identifying, monitoring, and preventing data loss incidents12. Rule sets are based on the organization's data classification, policies, and requirements, and they help to ensure that the DLP solution is aligned with the business objectives and risk appetite34. Configuring rule sets before enabling detection points, establishing exceptions workflow, or configuring reports helps to avoid false positives, false negatives, or unnecessary alerts5.
References
1: 3.13: Deploy a Data Loss Prevention Solution - Read the Docs
2: Plan and implement data loss prevention (DLP) [Guided] - NICCS
3: CONTINUOUS DIAGNOSTICS AND MITIGATION PROGRAM DATA PROTECTION ... - CISA
4: Continuous Diagnostics and Mitigation Program Technical ... - CISA
5: Data Loss Prevention Best Practices - ISACA Journal

The most important thing for an IS auditor to determine during the detailed design phase of a system development project is that acceptance test criteria have been developed. Acceptance test criteria define the expected functionality, performance and quality of the system, and are used to verify that the system meets the user requirements and specifications. The IS auditor should ensure that the acceptance test criteria are clear, measurable and agreed upon by all stakeholders. Program coding standards have been followed is something that the IS auditor should check during the coding or testing phase, not the detailed design phase.
Data conversion procedures have been established or the design has been approved by senior management are things that the IS auditor should verify during the implementation phase, not the detailed design phase. References: ISACA, CISA Review Manual, 27th Edition, 2018, page 323

The best source of information for an IS auditor to use as a baseline to assess the adequacy of an organization' s privacy policy is the local privacy standards and regulations. Privacy standards and regulations are legal requirements that specify how personal data should be collected, processed, stored, shared, and disposed of by organizations. By using local privacy standards and regulations as a baseline, the IS auditor can ensure that the organization's privacy policy complies with the applicable laws and protects the rights and interests of data subjects. Historical privacy breaches and related root causes, globally accepted privacy best practices, and benchmark studies of similar organizations are useful sources of information for improving an organization's privacy policy, but they are not as authoritative and relevant as local privacy standards and regulations. References: CISA Review Manual (Digital Version): Chapter 2 - Governance and Management of Information Technology