Answer: An engineering notebook
Explanation: An engineering notebook is a legal record or document kept by the engineers detailing the steps to be taken, the sketches, the calculations as well as the evaluation of the entire engineering design process. It contains all details of what ever is associated with the design process. Pages can neither be added nor removed in this notebook as it is dated and bonded.
It can be used in court of law as evidence if the need arises in legal or safety issues.