Which of the following is NOT a form of required supplementary information (RSI)?

Required supplementary information (RSI) includes various types of data that enhance the financial statements and provide additional context for users. Management's discussion and analysis, trend data on infrastructure condition, and claims development data for a public-entity risk pool all serve to give stakeholders insights into the financial health, operational efficiency, and risk management practices of an entity.

Management's discussion and analysis provides an overview of the financial performance and decisions affecting future results. Trend data on infrastructure condition reflects the long-term sustainability and investment needs of public assets. Claims development data for a public-entity risk pool offers vital information on the entity's liability and exposure to claims, which is essential for understanding fiscal responsibility regarding risk management.

The letter of transmittal, however, is not considered required supplementary information. Instead, it serves as an introductory document accompanying the financial statements, often summarizing significant issues and constraints. While it can provide valuable context, it does not fall into the category of required supplementary information that is expected to be included within the official financial reporting framework. This distinction is critical for understanding the types of information that are mandated for inclusion in financial reports versus those that serve conventional or supportive roles.