As asked here What is the difference between String and string in C#? you can use string and String in the code.
To have a common code style, we decided to use string when we create objects:
string name="Elvis";
and String when we use a static method:
String.Concat("Elvis", " lives");
I wanted to configure ReSharper in order to recognize this but I just find that I can configure it to use either the first or the second way: