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Rules and Practice Tips Regarding Official Notice at the U.S. Patent and Trademark Office

What is Official Notice?

MPEP §2103(VI) states that when a rejection is imposed, the “Office action should clearly communicate the findings, conclusions and reasons which support them.”  Examiners commonly satisfy this requirement by citing one or more prior art references allegedly teaching each of the limitations of a claim.

Occasionally, however, an Examiner may eschew documentary evidence on the record and instead opt to rely solely on his or her own opinion in support of a rejection.  In such a situation, the Examiner might “take official notice” to establish the veracity of an assertion made by the Examiner that a particular claim limitation is well-known in the art.

Official notice allows an Examiner to support a rejection by making a declaration of facts not in the record, but instead based on “common knowledge” in the art, according to MPEP §2144.03.  But only in very limited circumstances is taking official notice without documentary evidence to support an Examiner’s conclusion permissible.

MPEP §2144.03 provides a general rule of thumb for determining when it is appropriate for the Examiner to take official notice in making a rejection: “Official notice unsupported by documentary evidence should only be taken by the examiner where the facts asserted to be well-known, or to be common knowledge in the art are capable of instant and unquestionable demonstration as being well-known” (emphasis added).  As an example, the court ruled in In re Fox, 471 F.2d 1405, 1407, 176 USPQ 340, 341 (CCPA 1973), that it was proper to take official notice “of the fact that tape recorders commonly erase tape automatically when new ‘audio information’ is recorded on a tape which already has a recording on it.”  In In re Ahlert, 424 F.2d 1088, 1091, 165 USPQ 418, 420 (CCPA 1970), the court held it was proper to take official notice that “it is old to adjust intensity of a flame in accordance with the heat requirement.”

Conversely, MPEP §2144.03 instructs that official notice is inappropriate when making assertions of “technical facts in the areas of esoteric technology or specific knowledge of the prior art.”  The court in In re Eynde, 480 F.2d 1364, 1370, 178 USPQ 470, 474 (CCPA 1973), ruled that facts “constituting the state of the art are normally subject to the possibility of rational disagreement among reasonable men and are not amenable to the taking of such notice.”  When taking official notice of facts asserted to be common knowledge, the Examiner must provide specific factual findings predicated on sound technical and scientific reasoning to support his or her conclusion of common knowledge.  See In re Soli, 317 F.2d at 946, 37 USPQ at 801; In re Chevenard, 139 F.2d at 713, 60 USPQ at 241.

Additionally, the Examiner may not rely solely on official notice without documentary evidence as the principal evidence upon which a rejection is based, according to MPEP §2144.03.  Rather, as noted by the court in In re Ahlert, any officially noticed facts should serve only to “fill in the gaps” in an insubstantial manner to support the ground for rejection.  See In re Ahlert, 424 F.2d at 1092, 165 USPQ 421; In re Zurko, 258 F.3d at 1386, 59 USPQ2d at 1697.

Tips for Rebuttal

When reviewing a rejection supported by official notice, the Applicant should first verify that the basis underlying the Examiner’s decision to take official notice is set forth explicitly.  MPEP §2144.03 proclaims that the basis must be “clear and unmistakable” to permit the Applicant the ability to adequately traverse the rejection.  If support for the official notice is insufficiently defined, the Examiner’s use of official notice is improper.

If clear and unmistakable support for the official notice is present, the Applicant may challenge the official notice by specifically pointing out the supposed errors in the Examiner’s factual assertion.  See 37 C.F.R. §1.111(b).  A proper challenge must include arguments as to why the noticed fact is not considered to be common knowledge or well-known in the art.  (Applicants should recall that the noticed fact must be capable of instant and unquestionable demonstration as being well-known.)  By adequately traversing the use of official notice, the Examiner is compelled to provide documentary evidence in the next Office action if the rejection is to be maintained. See 37 C.F.R. §1.104(c)(2).  Applicants should review the next Office action to determine whether the Examiner has provided suitable documentary evidence, and if not, traverse any subsequent rejection based on MPEP §2144.03 and 37 C.F.R. §1.104(c)(2).  Failure to adequately traverse the official notice may result in the Examiner treating the statement of common knowledge or a fact well-known in the art as admitted prior art, per MPEP §2144.03.

Importantly, the taking of official notice of fact may not always be conspicuous.  As an example, an Examiner asserting that a given fact is common knowledge as a basis for a rejection without providing documentary evidence may be subject to the requirements associated with taking official notice, even if “official notice” is not expressly mentioned.  In such a case, Applicants should analyze the Examiner’s assertion pursuant to the official notice standards outlined in MPEP §2144.03, described herein, and/or request clarification from the Examiner.  Applicants therefore should be alert to the presence of documentary evidence, or lack thereof, whenever an Examiner attempts to take an official notice of fact, even in the absence of the phrase “official notice.”


In summary, official notice is an instrument by which Examiners rely on facts not in the record as a basis for rejection without providing documentary evidence.  Official notice can be taken only in limited circumstances where the facts asserted to be well-known or to be common knowledge in the art are “capable of instant and unquestionable demonstration as being well-known.”  Officially noticed facts should not be the principal evidence upon which a rejection is based, but rather should serve only an insubstantial role in supporting the rejection.  When reviewing an Examiner’s invocation of official notice, Applicants should note whether the basis underlying the Examiner’s decision to take official notice is “clear and unmistakable,” and determine whether the noticed fact is capable of instant and unquestionable demonstration as being well-known.  Any supposed errors in the official notice invocation should be specifically pointed out in the Applicant’s traversal.

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