Introduction

The decision so many people in the patent community waited for finally arrived on 28 May 2002. The Supreme Court of the United States, in Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 122 S. Ct. 1831, 62 U.S.P.Q.2d 1705 (2002), vacated the judgment of the United States Court of Appeals for the Federal Circuit ("Federal Circuit") that adopted a "complete bar" rule for prosecution history estoppel and, by doing so, arguably breathed life back into an ailing doctrine of equivalents. Or did it? And does the doctrine of equivalents lie beyond salvation, despite the Supreme Court's decision?

True, the Supreme Court reversed the Federal Circuit's earlier ruling that completely barred the application of the doctrine of equivalents to a claim limitation narrowed during prosecution for reasons related to patentability. But it also affirmed the part of the Federal Circuit's decision holding that a narrowing amendment made for any reason of patentability (e.g., prior art, written description, enablement, clarity, etc.) could trigger an estoppel.

So a crucial question remains: If an estoppel arises, to what extent will it limit application of the doctrine of equivalents? The Supreme Court's decision answers this question to some extent. But it creates additional questions in the process and leaves much to the Federal Circuit to sort out later.

Despite the frenzy of attention given to the Supreme Court's decision, in reality, Festo is only the tip of the iceberg. About seven years of Federal Circuit jurisprudence on claim construction and interpretation lurks just beneath the surface and has, to a large extent, reduced the practical viability of the doctrine of equivalents. Essentially unaffected by the Festo decision, this body of jurisprudence has and will likely continue to dramatically affect the enforceability of patents and the methods practitioners must use to prepare and prosecute patent applications.

Accordingly, in this article, we will not only explore the Supreme Court's decision in Festo, but also provide some practical tips for patent applicants to consider as the profession moves into the post-Festo era.

So What Did the Supreme Court Say in Festo?

So what did the Supreme Court say in Festo? Patent scholars and practitioners alike will probably make this question the subject of debate for some time to come. But in a relatively short opinion, the Supreme Court made two basic pronouncements: one dealing with activities that will trigger an estoppel and the second concerning the extent to which that estoppel will temper the expansive effects of equivalency.

First, the Supreme Court held that a narrowing amendment made for reasons of patentability could give rise to an estoppel. And those "patentability reasons" include not just reasons relating to prior art, but also issues related to 35 U.S.C. §112 (e.g., written description, enablement, clarity, etc.). Festo, 122 S. Ct. at 1840, 62 U.S.P.Q.2d at 1712. On what can create an estoppel, the Supreme Court therefore agreed with the Federal Circuit.

Second, regarding the extent of the estoppel, the Supreme Court held that such a determination "requires an examination of the subject matter surrendered by the narrowing amendment." Id. The Court, therefore, disagreed with the Federal Circuit's prior decision and vacated the "complete bar" rule. According to the Supreme Court, a narrowing amendment may not relinquish unforeseeable equivalents or foreclose equivalents of the invention that only have a peripheral relation to the reason for submitting the amendment.

The Supreme Court's holding, however, does not completely open the door for litigants seeking to apply the doctrine of equivalents. The Supreme Court clearly stated that a court can presume that the patentee made the narrowing amendment knowing that the "territory surrendered is not an equivalent of the territory [ultimately] claimed." Id. at 1842, 62 U.S.P.Q.2d at 1714. Essentially, a rebuttable presumption exists: By narrowing the claim, the patentee disclaims "the territory between the original claim and the amended claim." Id. at 1842, 62 U.S.P.Q.2d at 1713. Should an asserted equivalent fall within this surrendered territory, a patentee may overcome the presumption by establishing "that at the time of the amendment one skilled in the art could not reasonably be expected to have drafted a claim that would have literally encompassed the alleged equivalent." Id. at 1842, 62 U.S.P.Q.2d at 1714.

In Festo, the Supreme Court identifies several situations where an amendment cannot reasonably be viewed as surrendering a particular equivalent. First, the patentee can show that the asserted equivalent was "unforeseeable at the time of the application." Id. Such an equivalent would presumably include after-developed technology. Second, the patentee can show that the "rationale underlying the amendment" bears no more than a "tangential relation" to the asserted equivalent. Id. The Court, however, offered no example of what exactly would qualify as a "tangential relation." And third, what some view as a catch-all, the patentee can show any other reason why it "could not reasonably be expected to have described" in its claim the asserted equivalent. Id. Again, the Supreme Court provided no real guidance on this way of avoiding an estoppel.

The ultimate impact of the Supreme Court's decision will probably take some time to discern, especially as the Federal Circuit sorts out and interprets the intricacies of the decision.1 Nonetheless, several observations seem appropriate now.

First, even though the Supreme Court rejected the Federal Circuit's "complete bar" approach, the doctrine of equivalents clearly does not have the same force and effect it did five, seven, or even ten years ago. The Federal Circuit's prior decision encouraged licensees to reevaluate their agreements and determine whether a continuing need for a license existed. After the Supreme Court's decision in Festo, that type of reassessment still seems appropriate. Indeed, establishing that an amendment does not foreclose a court from even considering the doctrine of equivalents in a particular situation will likely prove quite daunting.

Second, the Supreme Court's decision does not change but actually reinforces the importance of meticulously preparing and prosecuting patent applications to secure the broadest scope of literal protection possible, without reliance on the doctrine of equivalents. Even before Festo, the Federal Circuit expressed its view that "as between the patentee who had a clear opportunity to negotiate broader claims but did not do so, and the public at large, it is the patentee who must bear the cost of its failure to seek protection for [a] foreseeable alteration of its claimed structure." Sage Prods., Inc. v. Devon Indus., Inc., 126 F.3d 1420, 1425, 44 U.S.P.Q.2d 1103, 1107 (Fed. Cir. 1997). The evidentiary burdens the Supreme Court's decision imposes on patentees only continues this trend in the law and the increasing demand for accountability in patent prosecution.

What Lurks Beneath the Festo Iceberg?

In soundly reversing the "complete" or "absolute" bar approach, the Supreme Court stated that "[t]he scope of a patent is not limited to its literal terms but instead embraces all equivalents to the claims described." Festo Corp., 122 S. Ct. at 1837, 62 U.S.P.Q.2d at 1710. Since the Supreme Court rendered its decision in Festo, the Federal Circuit has issued several opinions dealing with questions of infringement.2 In the Riles case, it affirmed a jury decision of infringement under the doctrine of equivalents on facts one might have expected the court to reverse through, for example, application of the All-Limitations Rule. 3 More recently, in the Eagle decision, the court reversed a summary judgment ruling of no infringement under the doctrine of equivalent due to prosecution history estoppel and further found that the All-Limitations Rule did not preclude a finding of infringement.

Do the Riles and Eagle cases herald a softening in the Federal Circuit's position that the doctrine of equivalents fails to provide certainty and notice to the public and that it must be narrowly circumscribed? Not likely. Despite the Supreme Court's decision and the later Riles and Eagle opinions, the doctrine of equivalents still remains a very uncertain remedy, and many believe that the Federal Circuit will not likely change its position in the near term. Indeed, the wealth of Federal Circuit jurisprudence narrowly construing claims, which the Supreme Court's decision in Festo left untouched, will continue to affect the way courts interpret claims and ultimately resolve issues of equivalency.

As a starting point, the Federal Circuit does not consider the doctrine of equivalents a talisman available to a patentee in all infringement inquiries. Schoell v. Regal Marine Indus., Inc., 247 F.3d 1202, 1210, 58 U.S.P.Q.2d 1450, 1456 (Fed. Cir. 2001). When considering the applicability of the doctrine of equivalents, the court professes to use the All-Limitations Rule, recognized in the Supreme Court's earlier decision in Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17, 40, 41 U.S.P.Q.2d 1865, 1876 (1997), and requires the presence of all limitations of the claimed invention, either identically or equivalently, in the alleged infringing product, process, etc. In practice, however, the Federal Circuit usually applies more of an "only literal infringement" rule, rarely getting beyond an analysis of literal infringement to effectively consider the "equivalency" part of the rule. See, e.g., Cooper Cameron Corp. v. Kvaerner Oilfield Prods., Inc., 291 F.3d 1317, 1322, 62 U.S.P.Q.2d 1846, 1850 (Fed. Cir. 2002) (an accused device with a port located above two plugs instead of "between the two plugs" did not infringe under a theory of equivalency because ignoring the term "between" would "vitiate that limitation and thereby run afoul of the all-limitations rule").

Leaving aside the "complete" bar approach to prosecution history estoppel, the Federal Circuit has also set other traps to snare unsuspecting patentees. Some practitioners call it "patent profanity," others call it "selling the invention," and still others, particularly in Europe, might even call it "describing a solution to a technical problem." Whatever its moniker, the Federal Circuit has consistently seized on a patentee's use of words like "critical," "essential," "important," and the like to steadfastly deny a claim for equivalency. See Bayer AG v. Elan Pharm. Research Corp., 212 F.3d 1241, 1253, 54 U.S.P.Q.2d 1711 (Fed. Cir. 2000) (statement that the claimed range produced "unique results and was a superior and inventive range" was a "clear and unmistakable surrender of subject matter outside the claimed range"); Pharmacia & Upjohn Co. v. Mylan Pharms., Inc., 170 F.3d 1373, 1377-78, 50 U.S.P.Q.2d 1033, 1037-38 (Fed. Cir. 1999) (arguing that "spray-dried lactose [was] a critical feature" of the invention, surrendering all embodiments not including spray-dried lactose). In the court's view, the use of these terms amounts to a "broad disclaimer of what the invention [is] not" and consequently estops the patentee from arguing equivalency for a product lacking the critical, important, or essential element. Pharmacia & Upjohn Co., 170 F.3d at 1378, 50 U.S.P.Q.2d at 1307.

Additional perils persist. For example, disclosing multiple embodiments of an invention but only claiming a portion of them, even if the unclaimed embodiments constitute clear equivalents, will lead to a dedication of those unclaimed embodiments to the public. See Johnson & Johnston Assocs. Inc. v. R.E. Serv. Co., Inc., 285 F.3d 1046, 1054, 62 U.S.P.Q.2d 1225, 1230 (Fed. Cir. 2002). And what about the test of "insubstantial differences" as a way of determining equivalency? Well, in today's environment, most patentees will not likely prevail in face of the Federal Circuit's precedent evincing a certain hostility to finding an accused product insubstantially different from the claimed product. See DeMarini Sports, Inc. v. Worth, Inc., 239 F.3d 1314, 1334, 57 U.S.P.Q.2d 1889, 1901 (Fed. Cir. 2001) (an accused baseball bat having an added external shell instead of the claimed insert was substantially different); Kustom Signals, Inc. v. Applied Concepts, Inc., 264 F.3d 1326, 1333, 60 U.S.P.Q.2d 1135, 1140 (Fed. Cir. 2001) (an accused traffic radar system that operated similarly to that claimed but always displayed the strongest target or the fastest target vehicle instead of providing a choice was considered substantially different).

And if all that is not enough, practitioners should keep in mind that many "would-be" arguments of equivalency can effectively falter when a court construes the scope of the patented invention, before it even considers any issue of infringement. In the interest of certainty and public notice, and completely independent of Festo, the Federal Circuit has been on a course of construing claims narrowly. In a case that some have pointed to as the start of this trend, Athletic Alternatives, Inc. v. Prince Manufacturing., Inc., 73 F.3d 1573, 1581, 37 U.S.P.Q.2d 1365, 1372 (Fed. Cir. 1996), the court held that where an equal choice exists between a broader and a narrower meaning of a claim term, "the notice function of the claim [is] best served by adopting the narrower meaning."

Will using a broad, generic term in the claim without any explicit definition in the specification retain the intended broad scope? Ever heard of "definition by implication"? Well, the use of a broad claim term can, in certain instances, be implicitly defined more narrowly if "a patentee uses [that] claim term throughout the entire patent specification in a manner consistent with only a single meaning." See Bell Atl. Network Servs., Inc. v. Covad Communications Group, Inc., 262 F.3d 1258, 1271, 59 U.S.P.Q.2d 1865, 1872 (Fed. Cir. 2001) (use of the broad term "mode" in the specification consistent with three specific embodiments implicitly defined and limited that term to those embodiments). Similarly, statements in the specification that a claimed element does not include a certain feature will place that feature beyond the patent's reach even where the claims, when read without reference to the specification, would embrace the feature in question. See Scimed Life Sys., Inc. v. Advanced Cardiovascular Sys., Inc., 242 F.3d 1337, 1340, 58 U.S.P.Q.2d 1059, 1062-63 (Fed. Cir. 2001).

Navigating Iceberg-Infested Waters

Clearly, Festo does not ease the difficulties and traps for those preparing and prosecuting patent applications. As described above, even without Festo, other legal principles may apply to limit the scope of the claims or the availability of the doctrine of equivalents based on language in the specification or acts or omissions during prosecution. The Supreme Court's statement that patent applicants should be "expected to draft claims encompassing readily known equivalents" serves as an additional wake-up call that the doctrine of equivalents cannot be relied on to save a patent. Festo Corp., 122 S. Ct. at 1842, 62 U.S.P.Q.2d at 1713. More than ever, patentees should draft claims and the specification with the expectation that the courts will limit the claims to their literal scope.

Tips for Drafting the Specification and Claims

By taking appropriate measures, patent applicants can position themselves to have the best chance of obtaining broad literal coverage for their claims and some scope of equivalents. Of course, the goal is to draft claims that will not require later amendments. Realizing this goal will involve a more extensive search of the prior art. The former practice of just drafting a broad claim and then amending it comes at a heavy price to the ultimate scope of protection obtained.

Narrowing amendments do not represent the only trap for unwary practitioners. Courts will carefully evaluate every word in the claims and specification in determining the patented invention's scope. The Federal Circuit recently shed light on its view of the importance of every word in CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 62 U.S.P.Q.2d 1658 (Fed. Cir. 2002). While the court emphasized that there is a heavy presumption that a claim term carries its ordinary and customary meaning, it explained that a court may constrict the ordinary meaning of a claim term in at least one of four ways: (1) if the patentee acted as his or her own lexicographer and clearly set forth a definition in the specification or prosecution history; (2) if the intrinsic evidence shows that the patentee distinguished the term from prior art on the basis of a particular embodiment, expressly disclaimed subject matter, or described a particular embodiment as important to invention; (3) if the term chosen by the patentee so deprives the claim of clarity as to require resort to the other intrinsic evidence for a definite meaning; or (4) if the patentee phrased the claim term in step or means-plus-function format so that the claim term will cover nothing more than the corresponding structure or steps disclosed in the specification, as well as equivalents thereof. Id. at 1366-67, 62 U.S.P.Q.2d at 1662-63. Thus, while a drafter may intend a broad meaning, the specification and/or prosecution may restrict that meaning.

Cognizant of the Federal Circuit's approach to claim interpretation, applicants should evaluate each word when preparing an application. If a term has multiple common definitions, or a special definition in the art that could differ from the ordinary meaning, consider specifically defining it in the specification. By doing so, the applicant controls the term's scope rather than leaving a court to determine some "ordinary meaning." Additionally, using equivalent, alternative, or expanding terms can broaden the definition of the word used in the claim and perhaps provide a later basis for a finding of literal infringement. Some ways to either broaden the meaning of a term or at least secure the scope initially intended could include: (1) using hypothetical examples; (2) explaining what the definition does not include; (3) describing how the industry would interpret a term; (4) describing the testing or measurement methodology for any numerical element; and (5) providing possible ways to test for infringement.

Applicants, however, should be wary to avoid using any "patent profanity" when drafting the specification. For instance, words in the specification like "critical," "key," "essential," "important," "superior," etc. to characterize aspects of the invention or emphasize features present in all embodiments of the invention should no longer or very rarely appear in the specification or prosecution history. These types of characterizations of the invention can come back to haunt a patentee when attempting to enforce its patent against an infringer who has modified the invention only slightly to remove one "important" or "key" element. See, e.g., Pharmacia & Upjohn Co., 170 F.3d at 1377-78, 50 U.S.P.Q.2d at 1037-38 (Fed. Cir. 1999). Along these same lines, an applicant may want to consider avoiding any characterizations or disparagements of the prior art in the specification and, more importantly, refrain from "selling" the invention by overly emphasizing objects, advantages, or purposes of the invention in the specification.

Further, perhaps to a greater extent than before, patent drafters should provide claims of varying scope, including generic, specific, and various scopes in between. The current legal environment not only places a stronger emphasis on providing broad and narrow claims, but also suggests more claims of intermediate scope or, at the very least, including the subject matter in the specification. A more detailed specification with the disclosure of various "fall back" positions may provide support not only for narrowing amendments but also for provisos or negative limitations that can prove very effective in surgically avoiding prior art.

In addition to claims of varying scope, applicants should consider using different claim types to cover the invention, such as claims drafted to cover an article of manufacture, a compound, a composition, a method of use, a method of preparation, the activity achieved by the compound, downstream products, systems, components of the system, combinations, subcombinations, and so on. This approach can provide ample ammunition for a patentee, especially when certain claims have been construed narrowly or simply avoided due to an alleged infringer's activities.

For mechanical and electrical inventions, a supplemental claiming approach should also include the use of step or means-plus-function limitations under 35 U.S.C. § 112, sixth paragraph. 4 The range of equivalents guaranteed under the statute for these types of claims may be the only equivalents available to a patentee, particularly if narrowing amendments have been made to the claims or a court determines that the patentee cannot rebut the presumption of surrender under Festo for an asserted equivalent. To support these claim limitations, the specification should broadly describe all known equivalents to the acts or structure related to the claimed steps or functions.

While providing a more detailed specification has its advantages for drafting claims, applicants should also keep in mind that disclosed but unclaimed embodiments would become dedicated to the public. See Johnson & Johnston, 285 F.3d at 1054, 62 U.S.P.Q.2d at 1230 (Fed. Cir. 2002). Therefore, drafters should confirm that each disclosed embodiment or alternative of the invention has at least one claim generally covering it to avoid a public dedication. 5

Prosecution Tips

One can view the start of the patent-examination process as an empty boat. With each amendment or argument made during prosecution, the applicant begins filling the boat with water. The applicant's goal: Exit the examination with a dry boat!

By extending the possibility of estoppel to § 112 rejections, 6 the Supreme Court made it that much more difficult to hold back the water. Consequently, trying everything possible before filing a narrowing amendment (e.g., traversing rejections rather amending the claims, conducting examiner interviews, appealing the rejections, etc.) has now taken on heightened importance.

Nonetheless, the reality remains that amendments are sometimes necessary and are still cheaper and faster than appeals. Naturally, the practitioner should try to avoid amending claims more narrowly than necessary. This particularly applies to certain invention parameters, such as temperature ranges or to chemical compounds or compositions with ranges. If the specification discloses a spectrum of values, amendments that slightly narrow the claimed range will have support under 35 U.S.C. § 112, first paragraph. Where a prior art species falls within the scope of a claimed genus, surgically excising that species from the claim by a proviso may prove somewhat more problematic in the U.S. than in Europe. But applicants should still try, and cases like In re Johnson, 558 F.2d 1008, 1018, 194 U.S.P.Q. 187, 196 (C.C.P.A. 1977) (written description support found for a claim to a genus minus specifically disclosed species), and In re Wertheim, 541 F.2d 257, 263-66, 191 U.S.P.Q. 90, 97-99 (C.C.P.A. 1976) (a broad disclosed range supported a subsequently claimed narrow range) should help.

When amending a claim, one should also consider providing statements in the prosecution history that the patentee can rely on in litigation to avoid or rebut the presumption of surrender. Responses with amendments to a rejection should, if possible, indicate that the amended language does not narrow the scope of the claim. This especially applies to amendments that overcome indefiniteness rejections by simply clarifying the original language. It can also apply where a claim amendment merely makes explicit what was already implicit, often easily demonstrated to an examiner by following the Federal Circuit's established rules of claim construction. See Trintec Indus., Inc. v. Top-U.S.A. Corp., 295 F.3d 1292, 1295, 63 U.S.P.Q.2d 1597, 1599 (Fed. Cir. 2002) (recognizing that claim terms may be implicitly or explicitly defined in the specification).

When narrowing the claim becomes necessary, consider identifying in the file history the reason or rationale behind the amendment. If the reasons for making the narrowing amendment are not clear from the file history, the patentee runs the risk that a court in reviewing the file will conclude that the amendment occurred for patentability purposes and that a sufficient basis to rebut the presumption of surrender does not exist. To the extent possible, one should state the reason in a way that maximizes the ability to later rebut any presumption of surrender under Festo.

Finally, applicants should make sure to coordinate global prosecution. On many occasions, the Federal Circuit has looked to related foreign priority documents and their prosecution to resolve the meaning of disputed claim terms. Indeed, it has paved the way for courts to use representations made to foreign patent offices in determining the applicability of prosecution history estoppel: "Though no authority is cited for the proposition that instructions to foreign counsel and a representation to foreign patent offices should be considered, and the varying legal and procedural requirements for obtaining patent protection in foreign countries might render consideration of certain types of representations inappropriate, there is ample authority in decisions of other courts and when such matters comprise relevant evidence they must be considered." Caterpillar Tractor Co. v. Berco, S.P.A., 714 F.2d 1110, 1116, 219 U.S.P.Q. 185, 188 (Fed. Cir. 1983); see also Tanabe Seiyaku Co., Ltd. v. U.S. Int'l Trade Comm'n, 109 F.3d 726, 41 U.S.P.Q.2d 1976 (Fed. Cir. 1997); Glaxo Group Ltd. v. Ranbaxy Pharmaceuticals Inc., 262 F. 3d 1333, 59 U.S.P.Q.2d 1950 (Fed. Cir. 1950)

Conclusion

Even though the Supreme Court rejected the "complete bar" rule, it did not totally resuscitate the already ailing doctrine of equivalents. The doctrine of prosecution history estoppel remains a trap for a patentee in enforcing a patent—a trap sometimes created from unintended consequences of a patent applicant's acts. More importantly, however, applicants should monitor the Federal Circuit's claim construction decisions. This jurisprudence, wrought with pitfalls for the unwary practitioner, places a premium on well-drafted claims and a detailed specification. In the post-Festo era, practitioners should consider modifying the way they have traditionally drafted and prepared patent applications to maximize the literal scope of their claims and also increase their chances of successfully invoking the doctrine of equivalents.

Copyright © Finnegan, Henderson, Farabow, Garrett & Dunner, LLP. Disclaimer: This article reflects the author's current understanding and views of the subject matter and has been written for scholarly pursuits. It is not meant to convey legal opinions or advice of any kind. The views expressed here should not be attributed, in whole or in part, to Finnegan, Henderson, Farabow, Garrett & Dunner, LLP, any of its attorneys, or any of its present or future clients. The firm and author disclaim any liability for any errors or omissions in this article. This article and its distribution do not establish any form of attorney-client relationship with the firm or with any of its attorneys.

1 Indeed the Federal Circuit has already started the process. It recently ordered the parties in the Festo case to submit briefs for an en banc hearing on several key questions, including: whether rebuttal of the presumption of surrender is a question of law or one of fact; what role a jury should play in determining whether a patent owner can rebut the presumption; and what factors are encompassed by the criteria set forth by the Supreme Court. Festo Corp. v. Shoketsu Kinzoku Kugyo Kabushiki Co., 2002 U.S. App. LEXIS 19734 (Fed. Cir. September 20, 2002). Undoubtedly, the answers to these questions and others raised by the Supreme Court's decision will ultimately control and shape the doctrine of equivalents for the foreseeable future.

2 See e.g., Semitool, Inc. v. Novellus Systems, Inc., 2002 U.S. App. LEXIS 14948 (Fed. Cir. July 23, 2002) (unpublished) (no infringement under the doctrine of equivalents after court applied "All-Limitations" Rule and prosecution history estoppel); Riles v. Shell Exploration and Production Co., 2002 U.S. App. LEXIS 15342 (Fed. Cir. July 31, 2002) (court affirmed a jury finding of infringement under the doctrine of equivalents); Allen Engineering Corp. v. Bartell Indus. Inc., 2002 U.S. App. LEXIS 15418 (Fed. Cir. August 1, 2002) (case remanded because the district court failed to perform a limitation-by-limitation analysis); The Read Corp. v. Powerscreen of America, Inc., 2002 U.S. App. LEXIS 16141 (Fed. Cir. August 7, 2002) (unpublished) (case remanded because lower court decision based on lack of evidence); Bowers v. Baystate Technologies, Inc., 2002 U.S. App. LEXIS 17184 (Fed. Cir. August 20, 2002) (literal infringement found); and Eagle Comtronics, Inc. v. Arrow Communications, Inc. 2002 U.S. App. LEXIS 19149 (Fed. Cir. September 17, 2002) (summary judgment of non-infringement due to prosecution history estoppel vacated).

3 See the dissenting opinion, which argued for application of the All-Limitations Rule to deny infringement. Riles, 2002 U.S. App. LEXIS at * 27.

4 The sixth paragraph of §112 states:

An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.

5 The type of tips discussed here for drafting the specification and claims will likely have the effect of substantially increasing the number of pages and claims in a application. In June 2002, the U.S. Patent and Trademark Office (USPTO) issued its Strategic Plan for the 21st Century containing several proposals that create financial disincentives to applicants that file voluminous specifications with an excessive number of claims. Consequently, practitioners should periodically monitor the Plan's progress and implementation to determine if and how it could impact on some of the practice tips discussed in this article.

6 As a reason for extending an estoppel to § 112 rejections, the Supreme Court relied on an applicant's decision to forego an appeal of the rejection. See Festo Corp., 122 S. Ct. at 1833, 62 U.S.P.Q.2d at 1711. In the past, an appeal within the USPTO did not present a very attractive option. Obtaining a decision could, in certain technologies, often take up to four to five years. Fortunately, the USPTO has cut the time to approximately one year from filing of the final appeal brief to a decision, making an appeal a much more attractive option now.