What are the default dynamics for all instruments in MS4?

What are the default dynamics for all instruments in MS4? When you create a new score, it begins 'clean,' without any specified dynamics. It seems that for strings, the default is 'mf,' as adding notes without dynamics sounds (at least to me) same to adding 'mf' dynamics to the initial measures. Is this the case for all instruments? In other words, is 'mf' the default dynamic for all instruments in MS4?