Values for yield and tensile strength

This is a pretty simple question. In office hours you mentioned that the 350-400 Mpa that they are asking for should be in reference to the nominal stress.

So my question is: Should the tensile strength they ask for also be in reference to the nominal stress or should it reference the true stress?

You will get all your material properties from the nominal stress-strain curve; elastic modulus, yield stress and ultimate tensile strength.