Does the phrase 'controlled substance' in U.S.S.C. § 4B1.2(b) include substances that are excluded from the Controlled Substances Act?

QUESTION PRESENTED A defendant convicted of violating the Controlled Substances Act is a “career offender” under the United States Sentencing Guidelines if, among other things, he has at least two prior felony convictions of either a crime of violence or a controlled substance offense. The guidelines define “controlled substance offense” as, in part, “an offense under federal or state law, punishable by imprisonment for a term exceeding one year that prohibits the manufacture, import, export, distribution, or dispensing of a controlled substance. The questions presented by this petition are: I Does the phrase “controlled substance” in U.S.S.C. § 4B1.2(b) include substances that are excluded from the Controlled Substances Act? Il. | When defining an operative, but undefined, term in the United States Sentencing Guidelines, should courts use analogous federal statutory definitions, state statutory definitions, or judge-made “natural meaning” of the term? ii