OPINION

On January 9, 2012, appellant Sid-dons — a federal prisoner currently incarcerated át FCI Fort Dix in New Jersey— filed a document entitled “Motion for Clarification of the Record” on his criminal docket in the United States District Court for the Eastern District of Pennsylvania. While emphasizing that he was “not asking for any adjustment or relief from his judgment and conviction,” Sid-dons demanded that the District Court clarify the factual bases of certain findings and rulings, such as its conclusions “as to the credibility and veracity of the testimony from” his former attorneys. Far from being a neutral filing with greater clarity as its sole aim, the motion obviously challenged the factual findings in question; moreover, it also requested relief that would imply the modification of Siddons’s conviction and sentence, such as by adjustment to the restitution order. 1 The District Court denied the motion as frivolous, and Siddons timely appealed.

We have jurisdiction under 28 U.S.C. § 1291; and, as we agree with the District Court that the motion is frivolous, we will summarily affirm its order. Murray v. Bledsoe, 650 F.3d 246, 248 (3d Cir. 2011) (per curiam); see also 3d Cir. L.A.R. 27.4; I.O.P. 10.6. Siddons points to no law, rule, or procedure that would compel the District Court to make the “corrections” he seeks. Indeed, focusing on “the function of the motion, [and] not its caption,” Turner v. Evers, 726 F.2d 112, 114 (3d Cir. 1984), it is clear that Siddons was attempting, in a circuitous fashion, to challenge his conviction or sentence. He continues to do so on appeal, arguing that the District Court “ignore[d] salient facts which would otherwise prove favorable” to him, and describing the adverse factual findings made as “[s]imply ... wrong.” The obvious time to raise these arguments, of course, was on direct appeal. See United States v. Siddons, 660 F.3d 699, 709 (3d Cir. 2011) (affirming the judgment of sentence). Sid-dons may otherwise bring his challenge through a permissible form of collateral attack, such as a motion to vacate under 28 U.S.C. § 2255. But he is in no position to demand that the District Court explain aspects of its ruling — many of which it has already clarified at great length, see United States v. Siddons, Criminal No. 07-717, 2009 WL 4729885, at *3-8, 2009 U.S. Dist. LEXIS 115193, at *8-21 (E.D.Pa. Dec. 10, 2009)—under the otherwise-innocuous label of “clarification.”

In sum, and for the foregoing reasons, we will summarily affirm the order of the District Court.