208 F.3d 577 (7th Cir. 2000)
UNITED STATES of America,    Plaintiff-Appellee,v.Gary V. MOORE, Aaron R. Wyatt, Michael A. Wyatt,  and Dwayne Anthony,    Defendants-Appellants.
Nos. 98-4296, 99-2676, 98-4323, & 99-2607
In the  United States Court of Appeals  For the Seventh Circuit
Argued January 14, 2000Decided March 29, 2000

Appeals from the United States District Court  for the Southern District of Illinois.  No. 98-40002-JPG--J. Phil Gilbert, Chief Judge.
Before Flaum, Easterbrook, and Ripple, Circuit Judges.
Easterbrook, Circuit Judge.


1
Four defendants,  convicted of crimes related to cocaine, have  received stiff sentences. Details of the offenses  are not relevant. One of the four appeals is not  properly here at all. Michael Wyatt pleaded  guilty, was sentenced to 192 months'  imprisonment, and appealed. Yet, as part of his  plea bargain, Michael Wyatt waived his right to  appeal, and nothing in the record suggests that  the waiver is involuntary or otherwise  problematic. We grant the prosecutor's motion to  dismiss his appeal, see United States v. Wenger,  58 F.3d 280 (7th Cir. 1995), and confine this  opinion to the contentions of the other  defendants.


2
Gary Moore, the only one of the four to stand  trial, sought to cross-examine Michael Wyatt  (testifying for the prosecution as part of his  plea bargain) about a handwritten note that bears  his signature and is notarized. This note reads:


3
I Michael Wyatt did Not agreed with Aaron  Wayt Wyatt or Gary MooRe or cory at any  time to sell Drug's


4
It is a peculiar note, and not only because it  looks like Michael Wyatt had trouble spelling his  own family name. The words "to sell Drug's" are  in a blue ink, while the rest of the test is in  black, raising the possibility that two people  (perhaps at different times) were responsible for  the text. Before counsel could get to any  questions about the authenticity and provenance  of this document, however, the district judge  excluded it from evidence on the ground that, by  failing to give it to the prosecutors before  trial, Moore's lawyer violated Fed. R. Crim. P.  16.


5
Moore's lawyer did not join issue on the  subject. He seemingly wanted the judge to  transcend the rules of evidence and criminal  procedure in general. That's not a winning line  of argument, for courts are entitled to exclude  evidence that should have been produced during  reciprocal discovery in criminal cases. Taylor v.  Illinois, 484 U.S. 400 (1988). Sticking to the  details would have done Moore more good, because  it is hard to see why Moore had to tip his hand  before trial. Of all the discovery requirements,  only Rule 16(b)(1)(A) speaks to materials such as  handwritten notes in a defendant's possession. It  says:


6
If the defendant requests disclosure under  subdivision (a)(1)(C) or (D) of this rule,  upon compliance with such request by the  government, the defendant, on request of  the government, shall permit the  government to inspect and copy or  photograph books, papers, documents,  photographs, tangible objects, or copies or portions thereof, which are within the  possession, custody, or control of the  defendant and which the defendant intends  to introduce as evidence in chief at the  trial.


7
Because Moore received discovery from the  prosecutor, he had to furnish in exchange  tangible evidence "which the defendant intends to  introduce as evidence in chief at the trial." Yet  Moore did not seek to use the note "as evidence  in chief at the trial." He tried to use it as a  prior inconsistent statement by Michael Wyatt  that would undermine his credibility in the  jurors' eyes. At oral argument in this court the  prosecutor contended that, because either Michael  Wyatt or someone else would have to establish the  authenticity of the document, this testimony  would be "evidence in chief". That assertion  sorely misunderstands what it means to offer  "evidence in chief" (or evidence in one's "case  in chief"). Preliminary issues of admissibility  are argued to the court. Fed. R. Evid. 104(a).  They are neither part of the case in chief nor  part of the defense. Rule 16(b)(1)(A) speaks to  how the evidence is used, not to how it is  introduced. Moore sought to use the note to  impeach the testimony of a witness for the  prosecution; it was not properly excludable under  Rule 16.


8
None of this does Moore any good, however,  because he did not argue the substance of Rule 16  in the district court, or for that matter in his  appellate brief. Only plain error could justify  reversal, and plain error entails, among other  things, a conclusion that enforcing the  forfeiture would condone a miscarriage of  justice. United States v. Olano, 507 U.S. 725,  736 (1993). No miscarriage occurred here. Moore  had ample opportunity to show the jurors Michael  Wyatt's shortcomings as a witness and as a  person. Quite apart from Michael Wyatt's  testimony, the evidence against Moore was  compelling, and a conviction was foreordained.


9
None of the defendants' other contentions  requires discussion. The most important of these,  an argument that the kind and quantity of drugs  must be treated as elements of the offense under  21 U.S.C. sec.841 in light of Jones v. United  States, 526 U.S. 227 (1999)--has been resolved by  an opinion issued after the oral argument of this  case. See United States v. Jackson, No. 98-2696  (7th Cir. Mar. 23, 2000). See also United States  v. Edwards, 105 F.3d 1179, 1180 (7th Cir. 1997),  affirmed, 523 U.S. 511 (1998). All of the rest  have been considered, and we approve the district  court's disposition of each. The appeal of  Michael Wyatt, No. 99-2607, is dismissed in  conformity with his plea agreement. In the other  three appeals, the judgments are affirmed.

