Affirmеd in part and dismissed in part by published opinion. Judge MOTZ wrote the opinion, in which Judge KING and Senior Judge HANSEN joined.
OPINION
In this appeal, we consider whether the United States Patent and Trademark Office may reject an application to register a trademark because the application contains multiple marks. For the reasons that follow, we conclude that it may. Accordingly, except for the appeal of a subsidiary point that we dismiss for lack of jurisdiction, we affirm the judgment of the district court.
I.
On March 19, 2001, Humanoids Group registered the mark 1 “Humanoids” with the Institut National de la Propriete In-dustrielle of the Republic of France. Under § 44(d) of the Lanham Act, 15 U.S.C. § 1126(d) (2000), Humanoids Group could claim priority for use of the mark in the United States as of this date, if it filed an application to register the mark with the Unitеd States Patent and Trademark Office (“PTO”) within the next six months. 2
On the last day of the six-month period, September 19, 2001, Humanoids Group filed an application with the PTO that contained the mark “Humanoids.” The application identified the mark submitted for consideration as “Humanoids,” stated that the application was filed pursuant to § 44(d) of the Lanham Act (which requires that the mark in the application and the previously-filed foreign mark be the same), and noted the serial number of the French trademark application for the mark “Humanoids.” But, the application also presented another mark, “Graphic Stories.” The application stated that “[a] drawing-page displaying the mark in conformance with 37 C.F.R. 2.52 is submitted with this application,” and, on the attached drаwing page, identified “Graphic Stories” as the mark it sought to obtain.
The PTO accepted Humanoids Group’s application and assigned it a September 19 filing date, but treated it as an application for the mark set forth on the drawing page — “Graphic Stories.” Because the six-month window expired the next day, the PTO’s failure to treat the application as one for the “Humanoids” mark caused Humanoids Group to lose the right to claim use of that mark in the United States as of its March 19 French filing date. Thus, another party’s May 4, 2001 application with the PTO to register the “Humanoids” mark gained that party priority over use of the mark in the United States.
In an effort to lay claim to the French filing date, and maintaining that it had *304 committed only a “scrivener’s error” in identifying “Graphic Stories” as its mark in the September 19 application, Humanoids Group petitioned the PTO to designate “Humanoids” as the mark submitted in that application. The PTO declined, pointing to its regulatory requirement that an application must present only one mark and to its policy of relaxing this requirement and granting a filing date to an application containing multiple marks only when the body of an application and its drawing page present different marks, and then only by permitting the mark presented on the drawing page to constitute the submitted mark. The PTO also noted the general interest in avoiding “impractical and time consuming” procedures and “delay” of “the entry of ... mark[s] into the Office’s automated systems.”
Humanoids Group then filed this action pursuant to the Administrative Procedure Act (“APA”), 5 U.S.C. § 701 et seq. (2000), seeking a judgment that the PTO’s denial of its petition violated the APA and an order substituting “Humanoids” as the mark submitted in the September 19 application. The district court granted summary judgment to the PTO. The court reasoned that PTO regulations limit an application to one mark at the time the application is filed, that the PTO acted reasonably in adopting a policy of granting a limited exception to this requirement by looking to the mark identified on the drawing page, and that the PTO correctly applied these regulations and policies in denying Humanoids Group’s petition. Humanoids Group appeals.
II.
An entity must complete two, distinct steps to register a mark with the PTO. First, the entity must submit an application that meets relevant requirements in order to receive a filing date. Second, the entity must meet more detailed requirements to secure final approval of the application to obtain registration. This case involves only the first of these steps.
In 1998, Congress enacted the Trademark Law Treaty Implementation Act, Pub.L. No. 105-330, 112 Stat. 3064 (1998) (codified in scattered sections of 15 U.S.C.). That statute affected several changes to the underlying Trademark Act of 1946 and instructed that “[t]he Director [of the PTO to] promulgate rules prescribing the requirements for the application and for obtaining a filing date herein” and “[t]he applicant [to] comply with such rules or regulations as prescribed by the Director.” 15 U.S.C. § 1051(a) (2000).
Consistent with this charge and the changes made by the Act, the PTO promulgatеd regulations providing that in order to receive a filing date, an application must contain:
(1) The name of the applicant;
(2) A name and address for the correspondence;
(3) A clear drawing of the mark;
(4) A listing of goods or services; and
(5) The filing fee....
37 C.F.R. § 2.21 (2003). When the PTO receives an application, it labels the application with a receipt date and then reviews the application for compliance with these “minimum requirements for receipt of a filing date.” Patent & Trademark Office, U.S. Dep’t of Commercе, Trademark Manual Examining Procedure (“PTO Manual”) § 203 (3d ed.2003). If the PTO determines that an application contains the required elements, the PTO assigns the application a filing date as of the date of receipt and enters the mark into its Trademark Electronic Search System, which the *305 public may access through the PTO’s website. 3
Humanoids Group contends that the PTO violated the APA in interpreting one of these “minimum requirements” — the rеquirement that the application contain “[a] clear drawing of the mark” — in the ease at hand and that the district court erred in holding to the contrary and granting summary judgment to the PTO. 37 C.F.R. § 2.21(a)(3). We review a grant of summary judgment de novo.
Inova Alexandria Hosp. v. Shalala,
III.
Humanoids Group argues that the PTO has misinterpreted the requirement, set forth in its regulation, that to receive a filing date an application must contain “[a] clear drawing of the mark.” 37 C.F.R. § 2.21. The PTO interprets this regulatory requirement to mean that an application must present
only
one drawing of one mark.
See In re Lavorazioni,
Generally, courts must defer to an agency’s interpretation of its own regulation, regarding that interpretation as “controlling unless plainly erroneous or inconsistent with the regulation.”
Auer v. Robbins,
A.
Humanoids Group contends that thе PTO’s interpretation of § 2.21 does not warrant deference for several reasons.
*306
First, Humanoids Group argues that the PTO did not adopt its interpretation in- a formal enough manner to merit judicial deference. In support of this argument, Humanoids Group points to the holding in
Christensen v. Hards Co.,
However, Humanoids Group also offers several arguments as to why, even if
Auer
generally requires judicial deference to an agency interpretation of its own regulations, we should not defer to the PTO here. Noting that deference under
Auer
is due “only when the language of the regulation is ambiguоus,”
Christensen,
Of course, determining whether a regulation or statute is ambiguous presents a legal question, which we determine
de novo. See, e.g., United States v. Mitchell,
Nor, contrary to Humanoids Group’s further contention, does the PTO’s interpretation of § 2.21 constitute a
“de facto
new regulation,”
Christensen,
Finally, Humanoids Group argues that we should not defer to the PTO’s interpretation of § 2.21 because the PTO has not offered the “reasoned” statement of this interpretation that
Auer
requires. As noted above, however, the PTO has explained its interpretation in a Commissioner’s decision,
In re Lavorazioni,
Thus, the deferential standard set forth in
Auer
governs our review of the PTO’s interpretation of § 2.21. We will, therefore, uphold the PTO’s interpretation unless Humanoids Group demonstratеs that this interpretation is “plainly erroneous or inconsistent with the regulation” itself.
Auer,
B.
Humanoids Group maintains that the PTO’s interpretation is both “plainly erroneous” and “inconsistent with” PTO regulations.
Auer,
First, it maintains that the PTO’s interpretation of § 2.21 conflicts with the Lan-ham Act and therefore is plainly erroneous. The Lanham Act describes two classes of applicants who “may request registration” of a trademark — owners of a “trademark [already] used in commerce,” and “[a] person who has a bona fide intention ... to use a trademark in commerce.” 15 U.S.C. § 1051(a)-(b). On the basis of these provisions, Humanoids Group argues that “the mark” referenced in § 2.21 necessarily means the mark that the applicant intends to register. From this, Humanoids Group extrapolates that the Lanham Aсt imposes an affirmative duty on the PTO to identify from an application the mark that the applicant intends to register, a duty that requires the PTO, when confronted with an application containing two or more marks, to contact the applicant and ascertain its intent. Humanoids Group maintains that the PTO has “ex-eis[ed] the [statutory] intent requirement” by rejecting applications that contain multiple marks without making such an inquiry. Brief of Appellant at 10-12.
Of course, the Lanham Act permits only “[a] person who has a bona fide intention ... to use a trademark in commerce [to] request registration of its trademark.” § 1051(b)(1). But nothing in the statute indicates that such an “intent requirement” gives rise to an affirmative duty on the part of the PTO. No provision of the Lanham Act specifies how the PTO must process an application setting forth multiple marks, some of which the applicant does not intend to register. 4 Certainly no *308 statutory provision precludes the approach adopted by the PTO of generally rejecting applications that present multiple marks. If anything, such an “intent requirement” would seem to place the onus on the applicаnt — here Humanoids Group — to submit a drawing of the mark that it intends to trademark, and only that mark. Thus, the PTO’s interpretation of § 2.21 does not contravene the Lanham Act.
Alternatively, Humanoids Group contends that the PTO’s interpretation of § 2.21 is inconsistent with the PTO’s own regulations. Brief of Appellant at 13-15. Specifically, Humanoids Group points out that § 2.21 (setting forth the minimum requirements for receipt of a filing dаte) does not have language expressly prohibiting multiple marks, but a subsequent regulation, § 2.52 (setting forth requirements related to the drawing for receipt of registration), does expressly provide that a drawing “must show only one mark.” From this, Humanoids Group reasons that while the “one mark” requirement must be satisfied to secure registration, it need not be satisfied to receive a filing date, аnd that § 2.21 cannot, therefore, be interpreted to contain the “one mark” requirement.
However, Humanoids Group fails to appreciate the differing context and purpose of the two regulations. Near the outset of the PTO’s regulations, § 2.21 sets forth the minimum requirements for receipt of a filing date and provides that one such requirement is that an application contain “[a] clear drawing of the mark.” Later, § 2.52, titled “Types of drawings and format for drawings,” sets forth detailed instructions on how a drawing and mark must be presented (how to represent marks with three dimensional features, with color, to demonstrate motion, etc.) to register a mark after the PTO has already granted a filing date to the application. § 2.52(b)(2). In an unenumerated paragraph preсeding the list of detailed instructions, § 2.52 states: “A drawing depicts .the mark sought to be registered. The drawing must show only one mark. The application must include a clear drawing of the mark when the application is filed.” § 2.52(a) (emphasis added). This brief, prefatory paragraph merely recaps basic requirements relating to “when the application is filed.” § 2.52(a). Section 2.52 then goes on to describe the additional and more complicated issues involving the mechanical details of rendering a drawing and mark for purposes of registration. Contrary to Humanoids Group’s assertion, then, § 2.52 entirely accords with (and, indeed, reiterates) the PTO’s interpreta *309 tion of its preceding companion regulation, § 2.21.
Thus, we find the PTO’s interpretation of § 2.21 — requiring the submission of only one mark — to be neither plainly erroneous nor inconsistent with the PTO’s regulations. 5
IV.
For all of these reasons, the judgment of the district court is
AFFIRMED IN PART AND DISMISSED IN PART.
Notes
. A “mark” is a word, phrase, symbol or design, or a combination thereof, that identifies and distinguishes the source of the goods or services of one party from those of others. 15 U.S.C. § 1127 (2000).
. Generally, the Lanham Act provides that an applicant seeking to register a trademark in the United States may claim a nationwide right of priority for use of the mark as of the filing date of its application with the PTO. See 15 U.S.C. § 1057(c) (2000). However, § 44(d) provides that an applicant who has registered a mark with certain foreign registries, including the Institut National, may claim priority in the United States as of the date of the foreign filing if the applicant files an application with the PTO within six months of that date. See id. § 1126(d).
. "Timely public notification of the filing of applicаtions is important because granting a filing date to an application potentially establishes a date of constructive use of the mark.” PTO Manual § 807. Constructive use “establishes a priority date with the same legal effect as the earliest actual use of a trademark at common law;” all ownership rights in a mark flow from prior use.
Allard Enters., Inc. v. Advanced Programming Res., Inc.,
. Humanoids Group also argues that we should reject the PTO's interpretation of
*308
§ 2.21 because requiring the PTO to ask applicants who submit applications containing multiple marks which mark they
intend
to register would constitutе a preferable interpretation. According to Humanoids Group, its interpretation would not unduly delay notice to the public or place an excessive burden on the PTO, yet would more accurately determine an applicant’s intent. Whether such an interpretation is preferable appears doubtful. If the PTO granted an applicant a filing date basеd on an application containing multiple marks, this would likely delay entry of the application into the electronic search system while the PTO attempted to identify the intended mark; any delay in public notice of the filing date might well "raise the risk of harm to third parties who may have acted in reliance on the record of pending applications.”
In re Tetrafluor Inc.,
. In its appellate briefs, Humanoids Group also challenged the PTO policy that permits an exception to the one mark rule in certain, limited circumstances.
See In re Lavorazioni,