title: Is it a good practice to add a "Null" or "None" member to the enum?
body: <p>When creating a new enum in C#, is it a good practice to have null member?</p>
  
  <p>If yes, do you give it the value of 0 by default? Would you call the null member Null or NULL? Do you strictly believe in Null or you don't have any problem with calling it something other than null. For instance None. Can you elaborate on your answer?</p>