Categorizations of data is critical in data management and usage. These "code sets" are used to categorize records and data for real world-entities:
the academic subject for a course
the grade level a student in enrolled in
the type of accommodation a student was provided for an assessment
All code sets depend on a context; said another way, there is no such thing as a code set that will work for all contexts. While we may think of some categorizations as being universal – such as grade levels - there are always and will always be variations, somewhere. This is part of the natural variation of the education ecosystem.
However, because there are always possible variation does not mean that there is not value to encouraging (perhaps strongly in some cases) usage and community governance of some sets of values. if we all agree to use the same set of values for grade level, that can hep us a great deal to share resources. There may be loss in converting our values to those values, but the benefits may be worth it.