References
Link to other related documents — test plans, design information, source code location, protocol documents, chip-level specifications, etc. [1] Also link to any external papers, hardware, protocols or ideas used in the document.
In this case the example links to the actual refernces used to elaborate this guide.
[1] Gottscho, M. (2024, February 20). A Template for Writing a Microarchitecture Specification. Retrieved from https://markgottscho.com/posts/2024/02/20/uarch-spec-template/
[2] Herveille, R. (2003, July 3). I²C-Master Core Specification (Rev. 0.9). OpenCores. Retrieved from https://github.com/freecores/i2c/blob/master/doc/i2c_specs.pdf