For instance, the personnel involved in research and development.
This is mostly classified information; to the outside, only the names of the team leaders would be disclosed. The public would know of the achievement but not who exactly did the R&D, who contributed more, and so on. However, internally, the information was accessible.
The achievement announcement from Steel Plant 307 mentioned "Academician Zhao Yi's report suggestions", indicating Zhao Yi was the main contributor to the achievement, with He Guilin's research team as the verifier, "having participated in designing the revised experimental process". The word "design" alone testified to their contribution.
Zhao Yi was the primary contributor, providing "theoretical contributions"; He Guilin's research team was second, responsible for designing and conducting the experiments that validated the entire process.
And thus the final results were obtained.