In order to establish a prima facie case, the IRS had only to make a "minimal" showing that it issued the summons for a legitimate purpose, and that the information sought in the summons was relevant to that purpose. Stuart v. United States, 813 F.2d 243, 248 (9th Cir. 1987) (citing United States v. Powell, 379 U.S. 48, 57-58, 85 S.Ct. 248, 254-55, 13 L.Ed.2d 112 (1964)). Declarations by the special agent that he was investigating Abrahams for possible improper conduct in preparing clients' returns and that the summoned material was necessary for the investigation satisfied the minimal standard.

Pp. 365-370. 813 F.2d 243, reversed and remanded. BRENNAN, J., delivered the opinion of the Court, in which REHNQUIST, C. J., and WHITE, MARSHALL, BLACKMUN, and STEVENS, JJ., joined, and in all but Part II-C of which O'CONNOR and KENNEDY, JJ., joined.

The primary purpose of Rule 44.1's notice requirement is to avoid unfairly surprising opposing parties. FED. R. CIV. P. 44.1 Advisory Committee's note; Stuart v. United States, 813 F.2d 243, 251 (9th Cir. 1987), rev'd on other grounds, 489 U.S. 353, 109 S.Ct. 1183, 103 L.Ed.2d 388 (1989); 9 Charles Alan Wright Arthur R. Miller, Federal Practice and Procedure § 2444 (2d ed. 1995) (explaining that Rule 44.1 "recognizes that notice should be given . . . in order to avoid unfair surprise either to the opposing party or to the court"). DPA cites Wright and Miller: "Written notice at trial may be reasonable if the issue was not apparent until then.

The primary purpose of Rule 44.1's notice requirement is to avoid unfairly surprising opposing parties. FED. R. CIV. P. 44.1 Advisory Committee's note; Stuart v. United States, 813 F.2d 243, 251 (9th Cir. 1987), rev'd on other grounds, 489 U.S. 353 (1989); 9 Charles Alan Wright & Arthur R. Miller, Federal Practice and Procedure §§ 2444 (2d ed. 1995) (explaining that Rule 44.1 "recognizes that notice should be given . . . in order to avoid unfair surprise either to the opposing party or to the court").

See In re Office of Inspector Gen., 933 F.2d 276, 277 (5th Cir. 1991); United States v. Kis, 658 F.2d 526, 535 (7th Cir. 1981) ("[W]e cannot stress too emphatically that these proceedings [regarding an IRS summons] are intended to be summary in nature."), cert. denied, 455 U.S. 1018, 102 S.Ct. 1712, 72 L.Ed.2d 135 (1982); Stuart v. United States, 813 F.2d 243, 250 (9th Cir. 1987), rev'd on other grounds, 489 U.S. 353, 109 S.Ct. 1183, 103 L.Ed.2d 388 (1989). 14.

Importantly, such material and testimony may be considered “at any time, whether or not submitted by a party.” Stuart v. United States , 813 F.2d 243, 250 (9th Cir. 1987), rev'd on other grounds by United States v. Stuart , 489 U.S. 353, 109 S.Ct. 1183, 103 L.Ed.2d 388 (1989) ; cf Kaho v. Ilchert , 765 F.2d 877, 881 (9th Cir. 1985) (noting that the traditional prohibition against considering materials not before an agency does not apply to consideration of foreign legal materials under Rule 44.1 ).Yet despite Rule 44.1's seemingly clear language, federal courts have largely remained hesitant to engage with questions of foreign law as fully and independently as they do with questions of domestic law—confusion and contradiction continue to plague the application of Rule 44.1. See, e.g. , Peter Hay, The Use and Determination of Foreign Law in Civil Litigation in the United States , 62 Am. J. Comp. L. Supp. 213, 235 (2014) (noting the lack of uniformity in application of Rule 44.1 ).

However, although Hatfield has raised and argued the issue concerning application of the foreign law's statute of limitations, neither side has mentioned the issue of England's tolling law, despite having the opportunity to do so. See Stuart v. United States, 813 F.2d 243, 251 (9th Cir. 1987) ("We realize that we may consider foreign law materials at any time, whether or not submitted by a party . . . [but,] [a]bsent special circumstances, parties should present issues of foreign law in their appellate briefs at the latest." (citations omitted)), rev'd on other grounds, 489 U.S. 353, 109 S.Ct. 1183, 103 L.Ed.2d 388 (1989).

Since it is a legal question, we review de novo the application of the political question doctrine. See Stuart v. United States, 813 F.2d 243, 246 (9th Cir. 1987), overruled on other grounds by United States v. Stuart, 489 U.S. 353, 109 S.Ct. 1183, 103 L.Ed.2d 388 (1989). Prudence, as well as separation-of-powers concerns, counsels courts to decline to hear "political questions."

The district court's construction of the Convention, like the construction of any statute, is a matter of law which we review de novo. See Stuart v. United States, 813 F.2d 243, 246 (9th Cir. 1987), rev'd on other grounds, 489 U.S. 353 (1989); see also Koreag, Controle et Revision S.A. v. Refco F/X Assocs., Inc., 961 F.2d 341, 347-48 (2d Cir. 1992). Statutory construction is a "holistic endeavor" and must account for the statute's "full text, language as well as punctuation, structure and subject matter."

Matters of foreign law may be determined by the court, which may consider any relevant material or source, including testimony. See Fed.R.Civ.P. 44.1; Stuart v. United States, 813 F.2d 243, 250-51 (9th Cir. 1987), rev'd on other grounds, 489 U.S. 353, 109 S.Ct. 1183, 103 L.Ed.2d 388 (1989). Unless recognized by the Luxembourg government, foreign judgments do not have any force in that country.