What's the use-case for specifying the underlying type in enums?

Question

What is the point of having

enum SomeEnum : byte // <----
{
  SomeValue = 0x01,
  ...
}

when you have to make a cast just to assign it t

Answer 1

From enum (C# Reference)

The underlying type specifies how much storage is allocated for each enumerator. However, an explicit cast is needed to convert from enum type to an integral type.