Defendant-Appellant Clifford Roy Tatum appeals from his guilty-plea conviction for conspiracy to possess with intent to distribute more than 50 grams of a mixture containing cocaine base and from his resulting sentence of 327 months’ imprisonment, followed by five years’ supervised release. We denied Tatum’s court-appointed counsel’s motion to withdraw and directed him to brief whether Tatum’s waiver of his right to appeal or to collaterally attack the plea, conviction, and sentence was knowing and voluntary; and *415 whether the district court admonished Tatum regarding the waiver provision as required by Federal Rule of Criminal Procedure 11. No other issues are raised.

Tatum has not shown that any Rule 11 violation by the district court amounted to plain error or that his waiver was not knowing and voluntary. See United States v. Dominguez Benitez , — U.S. —, 124 S.Ct. 2333, 159 L.Ed.2d 157 (2004); United States v. Portillo, 18 F.3d 290 (5th Cir. 1994). We need not address at this time whether a particular issue Tatum might attempt to raise in a post-conviction proceeding could be the proper subject of waiver. See United States v. White, 307 F.3d 336, 343 (5th Cir. 2002).

AFFIRMED.