I have decided to use a different approach. The ExifTag enum can now have descriptions. I added this for one value:
I can still use some help to add this for the other values.
[ExifTagDescription((ushort)1, "None")] [ExifTagDescription((ushort)2, "Inches")] [ExifTagDescription((ushort)3, "Cm")] ResolutionUnit = 0x0128,