Block = Header + Transactions
Transaction = inputs + outputs
We are not talking about stale blocks
the reference implementation
 M. A. Imtiaz, D. Starobinski, and A. Trachtenberg, “Characterizing Orphan Transactions in the Bitcoin Network,” in 2020 IEEE International Conference on Blockchain and Cryptocurrency (ICBC), May 2020, pp. 1–9.
 A. Groce, K. Jain, R. van Tonder, G. Tulajappa, and C. L. Goues, “Looking for lacunae in bitcoin core’s fuzzing efforts,” in International Conference on Software Engineering, 2022