Dr. Matthias Rath (“Rath”) appeals from the decisions of the Trademark Trial and Appeal Board (the “Board”) affirming the United States Patent and Trademark Office’s (“PTO”) refusal to register the marks “DR. RATH” and “RATH” (“the marks”) on the principal register. In re Rath, 2004 WL 161352, 2004 TTAB LEXIS 18 (Trademark Trial & App.Bd.Jan. 22, 2004); In re Rath, 2004 WL 161351, 2004 TTAB LEXIS 19 (Trademark Trial & App. Bd. Jan. 22, 2004). The decisions of the Board have been consolidated on appeal. We affirm.
BACKGROUND
Rath is a German citizen who applied to register the marks for goods and services including, inter alia, nutritional supplements, books, grains, and educational services. The applications were based upon ownership of a German trademark registration for the marks. The examiner refused to register the marks because the examiner found the marks to be primarily merely surnames. Section 2(e)(4) of the Lanham Act, 15 U.S.C. § 1052(e)(4), bars such marks from registration on the principal register.
On appeal to the Board, the marks were again found to be primarily merely surnames, and therefore not registrable on the principal register under section 2(e)(4) of the Lanham Act, absent proof of acquired distinctiveness under section 2(f).1 In re Rath, 2004 WL 161352 at * 4-5, 2004 TTAB LEXIS 18 at *9-10. The Board rejected Rath’s argument that the “primarily merely a surname” rule conflicts with the United States’ obligations under the Paris Convention, and therefore cannot be relied upon by the PTO to refuse a foreign applicant registration of a mark already registered in his country of origin. The Board also held that section 44 of the Lanham Act (which implements the Paris Convention) does not require registration of a mark that is primarily merely a surname, relying on our decision in In re Etablissements Darty et Fils, 759 F.2d 15 (Fed.Cir.1985). Rath appeals. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(4)(B).
DISCUSSION
I
We review the legal conclusions of the Board, including interpretations of the Lanham Act, 15 U.S.C. § 1051 et seq., without deference. In re Int’l Flavors & Fragrances Inc., 183 F.3d 1361, 1365 (Fed.Cir.1999).
II
Rath does not appeal the Board’s holdings that his marks are primarily merely *1209surnames under the meaning of section 2(e)(4). Indeed, he specifically “concedes that the marks are primarily, merely surnames.” (Br. of Appellant at 2.) Rather, he argues that the surname rule is at odds with the Paris Convention as applied to those holding foreign registrations.
Rath invokes article Qquinquies of the Paris Convention, which addresses the protection of marks registered in one member country in other member countries. It states in pertinent part:
A(l) Every trademark duly registered in the country of origin shall be accepted for filing and protected as is in the other countries of the Union, subject to the reservations indicated in this Article. Such countries may, before proceeding to final registration, require the production of a certificate of registration in the country of origin, issued by the competent authority. No authentication shall be required for this certificate.
B. Trademarks covered by this Article may be neither denied registration nor invalidated except in the folloiving cases:
1. when they are of such a nature as to infringe rights acquired by third parties in the country where protection is claimed;
2. ivhen they are devoid of any distinctive character, or consist exclusively of signs or indications which may serve, in trade, to designate the kind, quality, quantity, intended purpose, value, place of origin, of the goods, or the time of production, or have become customary in the current language or in the bona fide and established practices of the trade of the country where protection is claimed;
3. when they are contrary to morality or public order and, in particular, or such a nature as to deceive the public. It is understood that a mark may not be considered contrary to public order for the sole reason that it does not conform to a provision of the legislation on marks, except if such provision itself relates to public order.
Paris Convention for the Protection of Industrial Property, July 14, 1967, art. 6quinquies, 21 U.S.T. 1583, 1643-44 (emphases added).
Rath argues that he is exempt from the surname rule because it does not fall within any of the three enumerated exceptions to the registration of foreign marks within the Paris Convention, and he is therefore entitled to registration of his mark on the principal register. The PTO urges that surname marks are descriptive, and therefore “devoid of any distinctive character” within the meaning of the Paris Convention, such that no conflict exists between the requirements of the Lanham Act and the Paris Convention. We need not decide whether the surname rule conflicts with the Paris Convention because we find that the Paris Convention is not a self-executing treaty and requires congressional implementation.
Ill
It is well established that executory treaties (those treaties that are not self-executing) have no direct effect until implemented by domestic law. Whitney v. Robertson, 124 U.S. 190, 194, 8 S.Ct. 456, 31 L.Ed. 386 (1888). See generally 1 Ronald D. Rotunda & John E. Nowak, Treatise on Constitutional Law: Substance and Procedure § 6.6 (3d ed.1999) (discussing executory and self-executing treaties). Our predecessor court held that “[t]he Paris Convention was not ... self-executing and required implementing legislation.” Kawai v. Metlestics, 480 F.2d 880, 884 (Cust. & Pat.App.1973). We are *1210bound by the decisions of the Court of Customs and Patent Appeals (“CCPA”). South Corp. v. United States, 690 F.2d 1368, 1370 (Fed.Cir.1982) (en banc). Rath argues, however, that the older CCPA decision of Master, Wardens, Searchers, Assistants & Commonalty of Co. of Cutlers v. Cribben & Sexton Co., 40 C.C.P.A. 872, 202 F.2d 779 (Cust. & Pat.App.1953), conflicts with Kawai. In that case, the CCPA concluded that the Paris Convention “is part of our law and no special legislation in the United States was necessary to make it effective here.” Master, 202 F.2d at 783. We are obligated to follow the later decision in Kawai because “the Court of Customs and Patent Appeals always sat in banc and therefore later decisions overcome earlier inconsistent ones.” Celestaire, Inc. v. United States, 120 F.3d 1232, 1235 (Fed.Cir.1997).
It is also plain that Kawai is correct. The Paris Convention itself suggests that it is not self-executing. Article 25 states that “[a]ny country party to this Convention undertakes to adopt, in accordance with its constitution, the measures necessary to ensure the application of this Convention” and that “[i]t is understood that, at the time a country deposits its instrument of ratification or accession, it will be in a position under its domestic law to give effect to the provisions of this Convention.” Paris Convention for the Protection of Industrial Property, 21 U.S.T. at 1664; see also art. 6, id. at 1639 (“The conditions for the filing and registration of trademarks shall be determined in each country of the Union by its domestic legislation.”).
The majority of other Courts of Appeals that have considered the issue have also held that the Paris Convention is not self-executing. See, e.g., Int’l Café, S.A.L. v. Hard Rock Café Int’l, Inc., 252 F.3d 1274, 1277 n. 5 (11th Cir.2001); Mannington Mills, Inc. v. Congoleum Corp., 595 F.2d 1287, 1298-99 (3d Cir.1979); Ortman v. Stanray Corp., 371 F.2d 154, 157 (7th Cir.1967); see also S.Rep. No. 87-1019 (1961), reprinted in 1961 U.S.C.C.A.N. 3044, 3045 (“The provisions of the Convention of Paris are not self-executing, and legislation is therefore needed to carry into effect any provision not already in our present law.”); 19 Op. Att’y Gen. 273, 279 (1889) (In an opinion dated April 5, 1889, the Attorney General of the United States stated, “[The Paris Convention] is therefore not self-executing, but requires legislation to render it effective for the modification of existing laws.”). But see Vanity Fair Mills v. T. Eaton Co., 234 F.2d 633, 640-41 (2d Cir.1956) (stating that the Paris Convention is self-executing but does not create private rights for acts occurring in foreign countries).
Rath relies upon Davidoff Extension S.A. v. Davidoff Int’l, Inc., 221 U.S.P.Q. 465 (S.D.Fla.1983), for the proposition that the Paris Convention is self-executing. Davidoff holds that the Paris Convention is self-executing. However, we are not bound by this decision and we do not find it persuasive.2
*1211rv
Rath alternatively argues that section 44(e) of the Lanham Act is congressional legislation implementing the Paris Convention, and that section 44(e) itself requires registration because the Paris Convention requires registration. Whatever the situation with respect to other sections of the Lanham Act, section 44(e) cannot be construed as Rath urges.
Section 44(e) of the Lanham Act provides:
“(e) Registration on principal or supplemental register; copy of foreign registration. — A mark duly registered in the country of origin of the foreign applicant may be registered on the principal register if eligible, otherwise on the supplemental register herein provided. Such applicant shall submit, within such time period as may be prescribed by the Director, a certification or a certified copy of the registration in the county of origin of the applicant. The application must state the applicant’s bona fide intention to use the mark in commerce, but use in commerce shall not be required prior to registration.”
Lanham Act § 44(e), 15 U.S.C. § 1126(e) (2000) (emphasis added).
In cases of ambiguity, we interpret a statute such as section 44(e) of the Lanham Act as being consistent with international obligations. Murray v. The Schooner Charming Betsy, 6 U.S. (2 Crunch) 64, 118, 2 L.Ed. 208 (1804); Allegheny Ludlum Corp. v. United States, 367 F.3d 1339, 1348 (Fed.Cir.2004); Luigi Bormioli Corp. v. United States, 304 F.3d 1362, 1368 (Fed.Cir.2002). However, even assuming that the surname provision of the Lanham Act is inconsistent with the Paris Convention, section 44(e) is not susceptible to a construction that the surname rule is overcome where there has been an earlier foreign registration, and the Charming Betsy presumption is inapplicable. Congress did not simply adopt language incorporating the requirements of the convention in the Lanham Act. Rather it provided for registration of a foreign mark “if eligible.” A mark is not “eligible” for registration on the principal register under the statute unless it satisfies the section 2 requirements, including the surname rule.
The legislative history cited by the concurrence does not support a contrary conclusion. There is no question but that Congress generally intended section 44 of the Lanham Act to implement the Paris Convention.3' But this does not mean that Congress intended to do so in every respect or that it actually accomplished that objective in all respects or that it correctly understood the requirements of the Paris Convention in enacting section 44. To the extent that there was any consideration of the continued applicability of United States eligibility requirements to foreign marks, the legislative history cited by the concurrence suggests, at most, that Congress intended to permit registration of otherwise ineligible marks on the supple*1212mental register, not the principal register.4 There is simply no way to read this history as suggesting that Congress intended to require registration on the principal register despite United States eligibility requirements. If anything, the history confirms that the principal register was available to foreign registrants and United States citizens on equal terms — both had to meet the eligibility requirements of United States law.5
V
What is apparent from the face of the statute is confirmed by the cases as well. The issue whether section 44 acts to excuse an applicant from proving the distinctiveness of a surname mark as to the applicant’s goods arose in our earlier Darby case. Unlike this case, Darby did not involve an earlier foreign registration. Rather, the applicant in Darby filed an application, based on an earlier foreign application, to register the mark “DARTY” on the principal register, relying on section 44(d) of the Lanham Act to give it priority.6 Darby, 759 F.2d at 16, 18. The examiner refused to register the applicant’s mark on the principal register because the examiner found the mark primarily merely a surname, and the Board affirmed. Id. at 16. On appeal, this court again affirmed and held that a foreign applicant who claimed priority based on a foreign filed application under section 44(d) of the Lan-ham Act was not excused from the sur*1213name rule. Id. at 18. Instead, we found that
Section 44(d)(2) merely excuses certain foreign applicants from alleging use in commerce to secure registration under the statute. The section does not require that registration be afforded on the Principal Register, as opposed to the Supplemental Register, in the absence of a showing of secondary meaning acquired by use in this country.
Id. (footnote omitted). In so holding, we did not decide the question whether section 44 generally (or section 44(d) specifically) is coextensive with the Paris Convention. In a later section 44(d) case we stated that although “[a] section 44 applicant is excused from the statutory requirement that a mark must be used in commerce in or with the United States before such application is filed ... [a]n application under section 44 must, however, satisfy all the other provisions of the Act .... ” In re Mastic Inc., 829 F.2d 1114, 1115 (Fed.Cir.1987) (citations omitted).
We specifically noted in Darty that “[s]ection 44(e) specifically directs issuance of registration on the Principal Register only ‘if eligible.’ ” 759 F.2d at 18. The language of section 44(e) itself makes clear that the reference to eligibility pertains to eligibility for registration on the principal register, rather than eligibility under the Paris Convention. The leading treatise confirms this interpretation. McCarthy states that ‘the requirement of eligibility necessarily means “that the mark is subject to all the recognized statutory bars to U.S. registration.” 4 J. Thomas McCarthy, McCarthy on Trademarks and Unfair Competition § 29:13 (4th ed.2004). Section 2(e)(4) of the Lanham Act — prohibiting the registration of a mark that “is primarily merely a surname” on the principal register — is such an eligibility requirement. 15 U.S.C. § 1052(e)(4).
Rejecting the relevance of Darty, Rath and the concurrence rely on various cases that suggest that the implementing legislation and the Paris convention are coextensive. In this connection Rath, like the concurrence, relies primarily on the Board’s decision in Crocker National Bank v. Canadian Imperial Bank of Commerce, 223 U.S.P.Q. 909 (TTAB 1984). But Crocker did not directly address the interpretation of the “if eligible” clause of section 44(e). The actual holding of Crocker “is that a foreign national qualified under § 44(b) is entitled to an alternative basis for registration of a trademark registered in its country of origin without regard to whether such mark is in use prior to the application’s filing date.” Id. at 924.7 Broader language in Crocker stated that the Paris Convention “establish[ed] a minimum standard for all member countries as to what grounds for refusal of registration of any mark duly registered in the country of origin can be imposed by the other countries” and
that Section 44 is an independent provision, standing on its own feet with respect to applications for registration depending upon it and the conventions as the bases for United States registration, except for such formal requirements and conditions for registration as are consistent with the purposes of the conventions and the implementing statute.
Id. at 917, 920-21 (emphasis added). We have previously approved the holding in Crocker (“that regarding an application based on foreign registration under 15 *1214U.S.C. § 1126(e), [an] applicant need not meet the otherwise applicable statutory requirements regarding prior use of the mark”) but not the broader language. In re Compagnie Generale Mar., 993 F.2d 841, 843 n. 3 (Fed.Cir.1993).
Like Crocker, none of the other cases relied on by Rath or by the concurrence concludes that section 44(e) of the implementing legislation had the effect of eliminating the eligibility requirements of U.S. law or adopting the registration standards of article 6quinquies of the Paris Convention. Rather, those cases dealt with issues of priority or prior use — the effects of section 44(d) of the implementing legislation (dealing with preexisting foreign applications) on priority aspects of United States law (found in section 2(d) of the Lanham Act, 15 U.S.C. § 1052(d)), or the effects of the section 44 implementing legislation on the then-prevailing prior use requirement (which is a basis for registration).8 These authorities thus are of little use in addressing the scope and meaning of the “if eligible” requirement of section 44(e).
Thus, we conclude that while section 44(e), like section 44(d), affects United States priority or prior use rules, it is impossible to read section 44(e) to require the registration of foreign marks that fail to meet United States requirements for eligibility. Section 44 applications are subject to the section 2 bars to registration, of which the surname rule is one. McCarthy at § 29:13. Whether the surname rule conflicts with the requirements of the Paris Convention as applied to foreign registrants is a matter we need not decide.
CONCLUSION
The decision of the Board is
AFFIRMED.
COSTS
No costs.
. Section 2(f) provides, in pertinent part, that "[ejxcept as expressly excluded in subsections (a), (b), (c), (d), (e)(3), and (e)(5) of this section, nothing herein shall prevent the registration of a mark used by the applicant which has become distinctive of the applicant's goods in commerce.” Lanham Act § 2(f), 15 U.S.C. § 1052(f) (2000).
. Even less persuasive is Rath’s reliance on a German Federal Supreme Court case, (J.A. at 107-112 (reproducing Federal Supreme Court (Bundesgerichtshof) 05.04.1990 Case No. 1 ZB 7/89 ''FE”)), holding that Germany’s prohibition on registering letter trademarks, such as "FE”, conflicts with the requirements of the Paris Convention, and therefore cannot be applied against a foreign citizen of a Paris Union country.
Rath’s invocation of the Trade-Related Aspects of Intellectual Property agreement ("TRIPs”) (which incorporates the Paris Convention) is also unavailing. TRIPs is also not self-executing as 19 U.S.C. § 3512(a)(1) specifically provides that "[n]o provision of any of the Uruguay Round Agreements [including TRIPs], nor the application of any such provision to any person or circumstance, that is inconsistent with any law of the United States *1211shall have effect.” 19 U.S.C. § 3512(a)(1) (2000). Congress has also specifically precluded any person other than the United States from using TRIPs as a cause of action or a defense, and from challenging government action on the ground that such action is inconsistent with TRIPs. 19 U.S.C. § 3512(c)(1) (2000).
. Lanham Act § 45, 15 U.S.C. § 1127 (2000) ("The intent of this Act is ... to provide rights and remedies stipulated by treaties and conventions respecting trademarks, trade names, and unfair competition entered into between the United States and foreign nations.”); H.R.Rep. No. 78-603, at 4 (1943) ("This bill attempts to accomplish these various things: ... 2. To carry out by statute our international commitments ....”).
. The portion of the hearings cited in the concurrence expressed concern that a phrase in the part of the bill that would become section 44(e), which allowed registration on the supplemental register even if the mark was not registrable under section 2, might permit the registration of scandalous marks on the supplemental register. This concern was resolved by removing the phrase concerning registration on the supplemental register. Trade-Marlcs: Hearing on H.R. 4744 Before the Subcomm. On Trademarks of the House Comm, on Patents, 76th Cong. 169-71 (1939).
. The following exchange took place in the subcommittee hearings:
Mr. Byerly.... Now 1 is the principal register, and 23 is the supplemental register, so that [then section 44(c), current section 44(d) ] allows [a foreign applicant] to put [his mark] on either register, and naturally he will be guided as to which one he puts it on, as to which one our law allows, whether it is the sort of mark to go on one or the other....
Mr. Rogers. Dr. Ladas thought that subsection (d) [now (e) ] was desirable, to make it perfectly plain that if these foreigners could not get a registration under the principal register, they could under the supplemental register ....
The idea was to give the foreigner an opportunity, if he could, to qualify on the principal register, all right; if he could not, he could come under the supplemental register. It is just like our own citizens ....
Id. at 170. Interestingly, Dr. Ladas, referenced in the hearing, ultimately expressed the same view in his treatise' — that section 44(e) was designed to provide for registration on the supplemental register and "if eligible” on the principal register. 2 Stephen P. Ladas, Patents, Trademarks and Related Rights: National and International Protection § 572 (1975).
.The current section 44(d), 15 U.S.C. § 1126(d), provides, in pertinent part:
An application for registration of a mark ... filed by a person described in subsection (b) of this section who has previously duly filed an application for registration of the same mark in one of the countries described in subsection (b) of this section shall be accorded the same force and effect as would be accorded to the same application if filed in the United States on the same date on which the application was first filed in such foreign country: Provided, That—
(2) the application conforms as nearly as practicable to the requirements of this Act, including a statement that the applicant has a bona fide intention to use the mark in commerce.
. At the time Crocker was decided, the statutory definition of a trademark required that the mark be previously used. 15 U.S.C. § 1127 (1982 & Supp. II 1984). That definition was later amended, and now includes a mark that is used or a mark that a person has a bono fide intention to use in commerce. 15 U.S.C. § 1127 (2000).
. Two of the authorities relied on by the concurrence addressed the interplay between section 2(d), which prohibited the registration of a mark with a confusing resemblance to a mark already used by another in the United States, and section 44(d). See SCM Corp. v. Langis Foods Ltd., 539 F.2d 196 (D.C.Cir.1976); Allan Zelnick, Shaking the Lemon Tree: Use and the Paris Union Treaty, 67 Trademark Rep. 329 (1977). The SCM court held that section 44(d) accords a foreign applicant a six-month "right to priority” following the filing of its foreign application, but does not otherwise alter the requirements of section 2(d). SCM Corp., 539 F.2d at 201-02. The article opines upon the effect SCM might have on the continued vitality of the use requirement. Zelnick, 67 Trademark Rep. at 343-46.
The other authorities relied on by the concurrence deal almost exclusively with the prior use requirement. In re Compagnie Generale Mar., 993 F.2d at 843 n. 3 (affirming the holding of Crocker that the prior use requirement does not apply to 15 U.S.C. § 1126(e) applicants); Lane Ltd. v. Jackson Int’l Trading Co., 1994 WL 740491, 33 U.S.P.Q.2d 1351 (TTAB 1994) (discussing bona fide intent to use); Clairol Inc. v. Compagnie D'Editions Et De Propaganda Du Journal La Vie Claire-Cevic S.A., 24 U.S.P.Q.2d 1224 (TTAB 1991) (discussing bona fide intent to use); Crocker, 223 U.S.P.Q. at 924 (finding no prior use requirement for qualified foreign applicants); In re Certain Incomplete Trademark Applications, 1963 WL 7905, 137 U.S.P.Q. 69 (Dec. Comm'r Pat. 1963) (finding the prior use requirement applicable to foreign applicants); Ex parte Societe Fromageries Bel, 1955 WL 7225, 105 U.S.P.Q. 392 (Dec. Comm'r Pat. 1955) (finding that the prior use requirement does not apply when an applicant relies on a foreign registration); Daniel R. Bereskin & Aaron Sawchuk, Crocker Revisited: The Protection of Trademarks of Foreign Nationals in the United States, 93 Trademark Rep. 1199 (2003) (discussing the use requirement); Jeffery M. Samuels & Linda B. Samuels, The Changing Landscape of International Trademark Law, 27 Geo. Wash. J. Int'l L. & Econ. 433, 448-49 (1993-94) (noting the response of Congress to Crocker).