How does the TTB define a 'distinctive flavor' when classifying spirits, and why is this definition important?

The TTB (Alcohol and Tobacco Tax and Trade Bureau) doesn't provide a precise, quantifiable definition of 'distinctive flavor' but uses it as a functional descriptor in defining certain classes and types of distilled spirits. A 'distinctive flavor' is generally understood to mean a taste and aroma profile that clearly differentiates the spirit from neutral spirits or other standard classes of spirits. This distinction is based on the production methods, ingredients, and any....