Does 5 have to be in the middle of a magic square?

Could you elaborate on whether the number 5 absolutely must reside at the center of a magic square? Is there a mathematical principle or rule that dictates its placement, or is it merely a convention or a choice made by those constructing such squares? If 5 isn't mandatory in the middle, what are the implications for the properties and characteristics of the magic square? Additionally, are there scenarios where the center number is something other than 5, and if so, how does this affect the creation and validation of the square?