Single Choice Category Assignment

In certain situations there is a need for a user to select one and only one category value when assigning a category, consider rule scope with values Global, Regional, Local. The user would only be required to select one value but currently Category assignment allows for multiple value assignment with no limitation. Idea is to be able to flag a category in category admin to state that it is a single value choice rather than multi value select to prevent user incorrectly assigning more than one value.