concurring in the judgment.
The ground on which the district court based its ruling is not treated in this court’s per curiam opinion, leaving the remand in procedural and substantive limbo. The sole basis of the district court’s summary judgment was its adoption of the “omitted element test,” which was in turn derived from Microsoft’s incorrect statement of the law of written description.3 The issues concerning the “omitted element test” were fully presented on appeal, and our reversal of the summary judgment on a different ground does not answer the question that is central to this case. Our silence on whether this is a correct rule of law will be singularly mischievous, for it relates to Mr. Reiffin’s entitlement to his earlier filing date under 35 U.S.C. § 120, an issue that the parties expect to be raised on the case’s return to the district court.
The district court accepted Microsoft’s proposition that the patentee must include in every claim “each and every element” that was described as “part of his invention,” whether or not the element is necessary for patentability of the claim. Failure to do so, the district court held, invalidates the claims for noncompliance with the written description requirement of § 112 ¶ 1. That is not a correct statement of the law. Section 112 ¶ 2 instructs the applicant to “distinctly elaim[] the subject matter which the applicant regards as his invention.” This does not automatically require inclusion in every claim of every element that is part of the device or its operation.
It is standard for applicants to provide claims that vary in scope and in content, including some elements of a novel device or method, and omitting others. See Irving Kayton, 1 Patent Practice (6th ed.) 3.1, 3.3 (1995):
[Pjatent practitioners typically draft a series of claims approximating a spectrum of patent protection.... The first way in which a claim may be made narrower is by adding a limitation to it in the form of an additional element.
Claiming an invention in this manner does not raise an issue of compliance with § 112 ¶ 1. Indeed, the “omitted element test” threatens this venerable practice, which is also summarized in Ernest B. Lipscomb, III, 3 Lipscomb’s Walker on Patents 290-91 (1985):
[A] claim may cover an invention embracing the entire process, machine, manufacture, or composition of matter which is described in the specification, or it may cover such sub-processes or such sub-combinations of the invention as are new, useful and patentable.
See, e.g., Special Equipment Co. v. Coe, 324 U.S. 370, 65 S.Ct. 741, 89 L.Ed. 1006 (1945) (reversing the rejection of a sub-combination claim directed to the previously claimed invention less one element). While the specification must of course describe the claimed invention, it is well established that the claims need not include every component that is described in the specification. See Aro Mfg. Co. v. Convertible Top Replacement Co., 365 U.S. 336, 345, 81 S.Ct. 599, 5 L.Ed.2d 592 (1961) (There is “no legally recognizable or protected ‘essential’ element ... in a combination patent.”). The decision in Gentry Gallery, Inc. v. Berkline Corp., 134 F.3d 1473, 45 USPQ2d 1498 (Fed.Cir.1998), cited as authority by the district court, does not hold otherwise.
*1348In Gentry Gallery the issue was whether the written description, which described a specific location of a control console on a reclining sofa, adequately supported broad claims that were not limited to this location of the console; these broad claims were asserted by the patentee against a reclining sofa having the control console in a different location. This court held that the broad claims were not supported by the written description, and were invalid. As explained in Johnson Worldwide Assoc. v. Zebco Corp., 175 F.3d 985, 993, 50 USPQ2d 1607, 1613 (Fed.Cir.1999), “this court’s determination [in Gentry Gallery ] that the patent disclosure did not support a broad meaning for the disputed claim terms was premised on clear statements in the written description that described the location of a claim element ... as ‘the only possible location’ and that variations were ‘outside the stated purpose of the invention.’ ” The Gentry Gallery decision did not create a new requirement of claim content, or change the long-standing law and practice of claim drafting. Gentry Gallery is simply one of many decisions holding that, as quoted by the district court, “claims in an application which are broader than the applicant’s disclosure are not allowable.” Application of Sus, 49 C.C.P.A. 1301, 306 F.2d 494, 505, 134 USPQ 301, 310 (CCPA 1962) (citations omitted).
Microsoft also cites Tronzo v. Biomet, Inc., 156 F.3d 1154, 47 USPQ2d 1829 (Fed.Cir.1998), as supporting the “omitted element test.” In Tronzo, a first application was directed specifically and narrowly to a conical-shaped hip prosthesis; a continuation-in-part application then described additional shapes for the prosthesis, and for the first time presented generic claims that covered the additional shapes. This court explained that the generic claims were not entitled to the parent application’s filing date under § 120, for the generic claims were not supported by the written description in the parent application. See id. at 1158, 156 F.3d 1154, 47 USPQ2d at 1833 (it is “clear that the [parent specification] discloses only conical shaped cups and nothing broader.”). The generic claims were then invalidated, not because of any “omitted element,” but because of an intervening publication which rendered them anticipated.
Nor are the other cases on which Microsoft and the district court relied relevant. They concern reissued patents having broadened claims, the courts applying 35 U.S.C. § 251 and predecessor statutes which prohibit broadening reissue claims after two years, whether or not the broader claims are supported in the specification. For example, U.S. Industrial Chems., Inc. v. Carbide & Carbon Chem. Co., 315 U.S. 668, 677-78, 62 S.Ct. 839, 86 L.Ed. 1105 (1942) holds that the omission from the reissue claims of one of the steps or elements prescribed in the original claims, “thus broadening the claims to cover a new and different combination,” voids the reissue. Microsoft also relies on the authority of Olin v. Timken, 155 U.S. 141, 146-47, 15 S.Ct. 49, 39 L.Ed. 100 (1894), Huber v. Nelson Mfg. Co., 148 U.S. 270, 291-92, 13 S.Ct. 603, 37 L.Ed. 447 (1893), and Mathews v. Boston Machine Co., 105 U.S. 54, 58, 26 L.Ed. 1022 (1881). These reissue rulings have no relevance whatsoever to this case, which does not concern claim broadening by reissue.
When the claim is supported by the patent’s disclosure, is adequately distinguished from the prior art, and otherwise meets the statutory requirements of pat-entability, neither law nor policy requires that the claim contain all the elements described in the specification as part of the new machine or method. The district court’s controversial and incorrect decision should be confronted, not ignored.
. Microsoft stated: "This is a dispositive motion for summary judgment of invalidity based upon the patents’ failure to contain a 'written description’ of the claimed subject matter as required by 35 U.S.C. § 112 ¶ 1 .... Each and every element originally described by the inventor as being a part of his invention (sometimes referred to as ‘essential elements’) must appear in the claims ultimately issued in the patent. See, e.g., Gentry Gallery."