In which section of a requirements document would technical requirements be recorded?

The Requirements Catalogue (or the Requirements Specification section) is the comprehensive, organised list of all types of requirements. Technical Requirements are the non-functional constraints placed on the solution's design or build (e.g., specific hardware, operating system compatibility, integration protocols). While these inform other models, they are typically documented and tracked with other requirements (Functional and Non-functional) in the master Requirements Catalogue, often within the Non-functional or System Requirements section of the catalogue structure. Options A, B, and C are supporting documents or models, not the primary repository for a list of technical requirements.

(Reference: BCS Requirements Engineering – Requirements Catalogue Structure)