When a fuel is correctly categorized as taxable under the statute, it is ineligible also to be categorized as an alternative fuel, since the latter statute excludes fuels encompassed by the definition of taxable fuels. The statutory scheme is clear enough to defeat a plain meaning argument to the contrary. Any partial categorization of a blend as partially alternative would require a clear statement in the statute.
DISSENT:
The provision making the two categories mutually exclusive is in the excise tax portion of the Code, so the tax credit language in another area isn't bound by it, given plain meaning to the contrary. The excise provisions define the wide swath of the tax categories, and the credit provisions define particular instances. Ordinary meaning is the Star of Bethlehem.