Editing MPEP 715

<noinclude>{{MPEP Section|714|700|716}}</noinclude>

==[[MPEP 715|715 Swearing Back of Reference — Affidavit or Declaration Under 37 CFR 1.131]]== 

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37 CFR 1.131. Affidavit or declaration of prior invention.

(a)When any claim of an application or a patent under reexamination 
is rejected, the inventor of the subject matter of the 
rejected claim, the owner of the patent under reexamination, or the 
party qualified under §§ 1.42, 1.43, or 1.47, may submit an appropriate 
oath or declaration to establish invention of the subject matter 
of the rejected claim prior to the effective date of the reference 
or activity on which the rejection is based. The effective date of a 
U.S. patent, U.S. patent application publication, or international 
application publication under PCT Article 21(2) is the earlier of 
its publication date or date that it is effective as a reference under 
35 U.S.C. 102(e). Prior invention may not be established under 
this section in any country other than the United States, a NAFTA 
country, or a WTO member country. Prior invention may not be 
established under this section before December 8, 1993, in a 
NAFTA country other than the United States, or before January 1, 
1996, in a WTO member country other than a NAFTA country. 
Prior invention may not be established under this section if either:

(1)The rejection is based upon a U.S. patent or U.S. patent 
application publication of a pending or patented application to 
another or others which claims the same patentable invention as 
defined in § 41.203(a) of this title, in which case an applicant may 
suggest an interference pursuant to § 41.202(a) of this title; or

(2)The rejection is based upon a statutory bar.



(b)The showing of facts shall be such, in character and 
weight, as to establish reduction to practice prior to the effective 
date of the reference, or conception of the invention prior to the 
effective date of the reference coupled with due diligence from 
prior to said date to a subsequent reduction to practice or to the filing 
of the application. Original exhibits of drawings or records, or 
photocopies thereof, must accompany and form part of the affidavit 
or declaration or their absence must be satisfactorily 
explained.

37 CFR 1.131(a) has been amended to implement 
the relevant provisions of Public Law 103-182, 
107 
Stat. 2057 (1993) (North American Free Trade 
Agreement Act), Public Law 103-465, 108 Stat. 4809 
(1994) (Uruguay Round Agreements Act), and Public 
Law 106-113, 113 Stat. 1501 (1999) (American 
Inventors Protection Act), respectively. Under 
37 
CFR 1.131(a) as amended, which provides for the 
establishment of a date of completion of the invention 
in a NAFTA or WTO member country, as well as in 
the United States, an applicant can establish a date of 
completion in a NAFTA member country on or after 
December 8, 1993, the effective date of section 331 of 
Public Law 103-182, the North American Free Trade 
Agreement Act, and can establish a date of completion 
in a WTO member country other than a NAFTA 
member country on or after January 1, 1996, the 
effective date of section 531 of Public Law 103-465, 
the Uruguay Round Agreements Act (URAA). Acts 
occurring prior to the effective dates of NAFTA or 
URAA may be relied upon to show completion of the 
invention; however, a date of completion of the invention 
may not be established under 37 CFR 1.131before December 8, 1993 in a NAFTA country or 
before January 1, 1996 in a WTO country other than a 
NAFTA country.

If a country joined the WTO after January 1, 1996, 
the effective date for proving inventive activity in that 
country for the purpose of 35 U.S.C. 104 and 37 CFR 
1.131 is the date the country becomes a member of the 
WTO. See MPEP § 201.13 for a list that includes 
WTO member countries (the notation “Wo” indicates 
the country became a WTO member after January 1, 
1996).

Any printed publication or activity dated prior to an 
applicant’s or patent owner’s effective filing date, or 
any domestic patent of prior filing date, which is in its 
disclosure pertinent to the claimed invention, is available 
for use by the examiner as a reference, either 
basic or auxiliary, in the rejection of the claims of the 
application or patent under reexamination. In addition, 
patent application publications and certain international 
application publications having an effective 
prior art date prior to the application being examined 




 

may be used in a rejection of the claims. See MPEP 
§
 
706.02(a) and § 2136 - § 2136.03. 

Such a rejection may be overcome, in certain 
instances noted below, by filing of an affidavit or declaration 
under 37 CFR 1.131, known as “swearing 
back” of the reference.

It should be kept in mind that it is the rejection that 
is withdrawn and not the reference.

I.SITUATIONS WHERE 37 CFR 1.131 AFFIDAVITS 
OR DECLARATIONS CAN BE 
USED

Affidavits or declarations under 37 CFR 1.131 may 
be used, for example:

(A)To antedate a reference or activity that qualifies 
as prior art under 35 U.S.C. 102(a) and not under 
35 U.S.C. 102(b), e.g., where the prior art date under 
35 U.S.C. 102(a) of the patent, the publication or 
activity used to reject the claim(s) is less than 1 year 
prior to applicant’s or patent owner’s effective filing 
date. If the prior art reference under 35 U.S.C. 
102(a) is a U.S. patent or U.S. patent application publication, 
the reference may not be antedated if it 
claims the same patentable invention. See MPEP 
§ 715.05 for a discussion of “same patentable invention.”

(B)To antedate a reference that qualifies as prior 
art under 35 U.S.C. 102(e), where the reference has a 
prior art date under 35 U.S.C. 102(e) prior to applicant’s 
effective filing date, and shows but does not 
claim the same patentable invention. See MPEP 
§
 
715.05 for a discussion of “same patentable invention.” 
See MPEP § 706.02(a) and § 2136 through 
§
 
2136.03 for an explanation of what references qualify 
as prior art under 35 U.S.C. 102(e). 

II.SITUATIONS WHERE 37 CFR 1.131 AFFIDAVITS 
OR DECLARATIONS ARE INAPPROPRIATE


An affidavit or declaration under 37 CFR 1.131 is 
not appropriate in the following situations:

(A)Where the reference publication date is more 
than 1 year prior to applicant’s or patent owner’s 
effective filing date. Such a reference is a “statutory 
bar” under 35 U.S.C. 102(b) as referenced in 37 CFR 
1.131(a)(2). A reference that only qualifies as prior art 
under 35 U.S.C. 102(a) or (e) is not a “statutory bar.”

(B)Where the reference U.S. patent or U.S. 
patent application publication claims the same patentable 
invention. See MPEP § 715.05 for a discussion 
of “same patentable invention” and MPEP Chapter 
2300. Where the reference patent and the application 
or patent under reexamination are commonly owned, 
and the inventions defined by the claims in the application 
or patent under reexamination and by the 
claims in the patent are not identical but are not patentably 
distinct, a terminal disclaimer and an affidavit 
or declaration under 37 CFR 1.130 may be used to 
overcome a rejection under 35 U.S.C. 103. See MPEP 
§ 718. 

(C)Where the reference is a foreign patent for the 
same invention to applicant or patent owner or his or 
her legal representatives or assigns issued prior to the 
filing date of the domestic application or patent on an 
application filed more than 12 months prior to the filing 
date of the domestic application. See 35 U.S.C. 
102(d).

(D)Where the effective filing date of applicant’s 
or patent owner’s parent application or an International 
Convention proved filing date is prior to the 
effective date of the reference, an affidavit or declaration 
under 37 CFR 1.131 is unnecessary because the 
reference should not have been used. See MPEP § 
201.11 to §
 
201.15.

(E)Where the reference is a prior U.S. patent to 
the same entity, claiming the same invention. The 
question involved is one of “double patenting.”

(F)Where the reference is the disclosure of a 
prior U.S. patent to the same party, not copending. 
The question is one of dedication to the public. Note 
however, In re Gibbs, 437 F.2d 486, 168 USPQ 578 
(CCPA 1971) which substantially did away with the 
doctrine of dedication.

(G)Where applicant has clearly admitted on the 
record that subject matter relied on in the reference is 
prior art. In this case, that subject matter may be used 
as a basis for rejecting his or her claims and may not 
be overcome by an affidavit or declaration under 37 
CFR 1.131. In re Hellsund, 474 F.2d 1307, 177 USPQ 
170 (CCPA 1973); In re Garfinkel, 437 F.2d 1000, 
168 USPQ 659 (CCPA 1971); In re Blout, 333 F.2d 
928, 142 USPQ 173 (CCPA 1964); In re Lopresti, 
333 
F.2d 932, 142 USPQ 177 (CCPA 1964).

(H)Where the subject matter relied upon is prior 
art under 35 U.S.C. 102(f).

(I)Where the subject matter relied on in the reference 
is prior art under 35 U.S.C. 102(g). 37 CFR 
1.131 is designed to permit an applicant to overcome 
rejections based on references or activities which are 
not statutory bars, but which have dates prior to the 
effective filing date of the application but subsequent 
to the applicant’s actual date of invention. However, 
when the subject matter relied on is also available 
under 35 U.S.C. 102(g), a 37 CFR 1.131 affidavit or 
declaration cannot be used to overcome it. In re Bass, 
474 F.2d 1276, 177 USPQ 178 (CCPA 1973). This is 
because subject matter which is available under 
35 
U.S.C. 102(g) by definition must have been made 
before the applicant made his or her invention. By 
contrast, references under 35 U.S.C. 102(a) and (e), 
for example, merely establish a presumption that their 
subject matter was made before applicant’s invention 
date. It is this presumption which may be rebutted by 
evidence submitted under 37 CFR 1.131.

(J)Where the subject matter corresponding to a 
lost count in an interference is either prior art under 
35 U.S.C. 102(g) or barred to applicant by the doctrine 
of interference estoppel. In re Bandel, 348 F.2d 
563, 146 USPQ 389 (CCPA 1965); In re Kroekel, 
803 
F.2d 705, 231 USPQ 640 (Fed. Cir. 1986). See 
also In re Deckler, 977 F.2d 1449, 24 
USPQ2d 1448 
(Fed. Cir. 1992) (Under the principles of res judicataand collateral estoppel, applicant was not entitled to 
claims that were patentably indistinguishable from the 
claim lost in interference even though the subject matter 
of the lost count was not available for use in an 
obviousness rejection under 35 U.S.C. 103). But see 
In re Zletz, 893 F.2d 319, 13 USPQ2d 1320 (Fed. Cir. 
1989) (A losing party to an interference, on showing 
that the invention now claimed is not “substantially 
the same” as that of the lost count, may employ the 
procedures of 37 CFR 1.131 to antedate the filing date 
of an interfering application). On the matter of when a 
“lost count” in an interference constitutes prior art 
under 35 U.S.C. 102(g), see In re McKellin, 529 F.2d 
1342, 188 USPQ 428 (CCPA 1976) (A count is not 
prior art under 35 U.S.C. 102(g) as to the loser of an 
interference where the count was lost based on the 
winner’s foreign priority date). Similarly, where one 
party in an interference wins a count by establishing a 
date of invention in a NAFTA or WTO member country 
(see 35 U.S.C. 104), the subject matter of that 
count is unpatentable to the other party by the doctrine 
of interference estoppel, even though it is not 
available as statutory prior art under 35 
U.S.C. 
102(g). See MPEP § 2138.01 and § 2138.02.

III.REFERENCE DATE TO BE OVERCOME

The date to be overcome under 37 CFR 1.131 is the 
effective date of the reference (i.e., the date on which 
the reference is available as prior art).

A.U.S. Patents, U.S. Patent Application Publications, 
and International Application Publications


See MPEP § 706.02(a), § 706.02(f)(1), and §
 
2136through §
 
2136.03 for a detailed discussion of the 
effective date of a U.S. patent, U.S. patent application 
publication, or WIPO publication of an international 
application as a reference.

U.S. patents, U.S. patent application publications, 
and WIPO publications of international applications 
are available as prior art under 35 U.S.C. 102(e)
against all patent applications and patents under reexamination.


The effective date of a domestic patent when 
used as a reference is not the foreign filing date to 
which the application for patent may have been entitled 
under 35 U.S.C. 119(a) during examination. In re 
Hilmer, 359 F.2d 859, 149 USPQ 480 (CCPA 1966). 
Therefore, the date to be overcome under 37 CFR 
1.131 is the effective U.S. filing date, not the foreign 
priority date. When a U.S. patent or U.S. patent application 
publication reference is entitled to claim the 
benefit of an earlier filed application, its effective filing 
date is determined under 35 U.S.C. 102(e). See 
MPEP §
 
706.02(a), § 706.02(f)(1), and § 2136through §
 
2136.03.

B.Foreign Patents

See MPEP § 2126 through § 2127 regarding date of 
availability of foreign patents as prior art.

C.Printed Publications

A printed publication, including a published foreign 
patent application, is effective as of its publication 
date, not its date of receipt by the publisher. For 
additional information regarding effective dates of 




 

printed publications, see MPEP § 2128 through 
§
 
2128.02.

D.Activities

An applicant may make an admission, or submit 
evidence of use of the invention or knowledge of the 
invention by others, or the examiner may have personal 
knowledge that the invention was used or 
known by others in this country. See MPEP 
§
 
706.02(c) and § 2133.03. The effective date of the 
activity used to reject the claim(s) is the date the 
activity was first known to have occurred.

FORM PARAGRAPHS

Form paragraphs 7.57-7.64 may be used to respond 
to 37 CFR 1.131 affidavits.

¶ 7.57 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective- Heading

The [1] filed on [2] under 37 CFR 1.131 has been considered 
but is ineffective to overcome the [3] reference.

Examiner Note:

1.In bracket 1, insert either --affidavit-- or --declaration--.

2.This form paragraph must be followed by one or more of 
form paragraphs 7.58 to 7.63 or a paragraph setting forth proper 
basis for the insufficiency, such as failure to establish acts performed 
in this country, or that the scope of the declaration or affidavit 
is not commensurate with the scope of the claim(s).



¶ 7.58 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective, Claiming Same Invention

The [1] reference is a U.S. patent or U.S. patent application 
publication of a pending or patented application that claims the 
rejected invention. An affidavit or declaration is inappropriate 
under 37 CFR 1.131(a) when the reference is claiming the same 
patentable invention, see MPEP Chapter 2300. If the reference 
and this application are not commonly owned, the reference can 
only be overcome by establishing priority of invention through 
interference proceedings. See MPEP Chapter 2300 for information 
on initiating interference proceedings. If the reference and 
this application are commonly owned, the reference may be disqualified 
as prior art by an affidavit or declaration under 37 CFR 
1.130. See MPEP § 718.

Examiner Note:

1.If used to respond to the submission of an affidavit under 37 
CFR 1.131, this paragraph must be preceded by paragraph 7.57.

2.This form paragraph may be used without form paragraph 
7.57 when an affidavit has not yet been filed, and the examiner 
desires to notify applicant that the submission of an affidavit 
under 37 CFR 1.131 would be inappropriate.



¶ 7.59 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective, Insufficient Evidence of Reduction to Practice 
Before Reference Date

The evidence submitted is insufficient to establish a reduction 
to practice of the invention in this country or a NAFTA or WTO 
member country prior to the effective date of the [1] reference. [2]

Examiner Note:

1.This form paragraph must be preceded by form paragraph 
7.57.

2.An explanation of the lack of showing of the alleged reduction 
to practice must be provided in bracket 2.

¶ 7.60 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective, Reference Is a Statutory Bar

The [1] reference is a statutory bar under 35 U.S.C. 102(b) and 
thus cannot be overcome by an affidavit or declaration under 37 
CFR 1.131.

Examiner Note:

This form paragraph must be preceded by form paragraph 7.57.

¶ 7.61 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective, Insufficient Evidence of Conception

The evidence submitted is insufficient to establish a conception 
of the invention prior to the effective date of the [1] reference. 
While conception is the mental part of the inventive act, it must be 
capable of proof, such as by demonstrative evidence or by a complete 
disclosure to another. Conception is more than a vague idea 
of how to solve a problem. The requisite means themselves and 
their interaction must also be comprehended. See Mergenthaler v. 
Scudder, 1897 C.D. 724, 81 O.G. 1417 (D.C. Cir. 1897). [2]

Examiner Note:

1.This form paragraph must be preceded by form paragraph 
7.57.

2.An explanation of the deficiency in the showing of conception 
must be presented in bracket 2.

3.If the affidavit additionally fails to establish either diligence 
or a subsequent reduction to practice, this form paragraph should 
be followed by form paragraph 7.62 and/or 7.63. If either diligence 
or a reduction to practice is established, a statement to that 
effect should follow this paragraph.

¶ 7.62 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective, Diligence Lacking

The evidence submitted is insufficient to establish diligence 
from a date prior to the date of reduction to practice of the [1] reference 
to either a constructive reduction to practice or an actual 
reduction to practice. [2]

Examiner Note:

1.This form paragraph must be preceded by form paragraph 
7.57.

2.If the affidavit additionally fails to establish conception, this 
paragraph must also be preceded by form paragraph 7.61. If the 




 

affidavit establishes conception, a statement to that effect should 
be added to this paragraph.

3.If the affidavit additionally fails to establish an alleged 
reduction to practice prior to the application filing date, this paragraph 
must be followed by form paragraph 7.63. If such an 
alleged reduction to practice is established, a statement to that 
effect should be added to this paragraph.

4.An explanation of the reasons for a holding of non-diligence 
must be provided in bracket 2.

5.See MPEP § 715.07(a), Ex parte Merz, 75 USPQ 296 (Bd. 
App. 1947), which indicates that diligence is not required after 
reduction to practice.

¶ 7.63 Affidavit or Declaration Under 37 CFR 1.131: 
Ineffective, Insufficient Evidence of Actual Reduction to 
Practice

The evidence submitted is insufficient to establish applicant’s 
alleged actual reduction to practice of the invention in this country 
or a NAFTA or WTO member country after the effective date of 
the [1] reference. [2].

Examiner Note:

1.This form paragraph must be preceded by form paragraph 
7.57.

2.If the alleged reduction to practice is prior to the effective 
date of the reference, do not use this paragraph. See form paragraph 
7.59.

3.If the affidavit additionally fails to establish either conception 
or diligence, form paragraphs 7.61 and/or 7.62 should precede 
this paragraph. If either conception or diligence is 
established, a statement to that effect should be included after this 
paragraph.

4.An explanation of the lack of showing of the alleged reduction 
to practice must be given in bracket 2.

¶ 7.64 Affidavit or Declaration Under 37 CFR 1.131: 
Effective To Overcome Reference

The [1] filed on [2] under 37 CFR 1.131 is sufficient to overcome 
the [3] reference.

Examiner Note:

1.In bracket 1, insert either --affidavit-- or --declaration--.

2.In bracket 2, insert the filing date of the affidavit or declaration.


3.In bracket 3, insert the name of the reference.

715.0137 CFR 1.131 Affidavits Versus37 CFR 1.132 Affidavits

The purpose of a 37 CFR 1.131 affidavit or declaration 
is to overcome a prior art rejection by proving 
invention of the claimed subject matter by applicant 
prior to the effective date of the reference or activity 
relied upon in the rejection.

In some situations, an applicant may, alternatively, 
be able to overcome prior art rejections relying on references 
or activities which are available as prior art 
under 35 U.S.C. 102(a) or references which are available 
as prior art under 35 U.S.C. 102(e) by proving 
that the subject matter relied upon in the reference or 
activity was applicant’s own invention. 

Similarly, where the reference relied upon in a 
35 
U.S.C. 103 rejection qualifies as prior art only 
under 35 U.S.C. 102(f) or (g), or, in an 
application 
filed on or after November 29, 1999, 
under 35 U.S.C. 102(e), applicant may be able to 
overcome this rejection by proving that the subject 
matter relied upon and the claimed invention were 
commonly owned or subject to common assignment 
at the time the later invention was made. See MPEP 
§
 
706.02(l)(1) through §
 
706.02(l)(3).

715.01(a)Reference Is a Joint Patent or 
Published Application to Applicant 
and Another [R-2]

When subject matter, disclosed but not claimed in a 
patent or application publication filed jointly by S and 
another, is claimed in a later application filed by S, the 
joint patent or application publication is a valid reference 
under 35 U.S.C. 102(a) or (e) unless overcome 
by affidavit or declaration under 37 CFR 1.131or an unequivocal declaration under 37 CFR 1.132 by 
S that he/she conceived or invented the subject matter 
disclosed in the patent or application publication and 
relied on in the rejection. In re DeBaun, 687 F.2d 459, 
214 USPQ 933 (CCPA 1982). See MPEP § 716.10 for 
a discussion of the use of 37 CFR 1.132 affidavits or 
declarations to overcome rejections by establishing 
that the subject matter relied on in the patent or application 
publication was the invention of the applicant. 
Disclaimer by the other patentee or applicant of the 
application publication should not be required but, if 
submitted, may be accepted by the examiner. 

Although affidavits or declarations submitted for 
the purpose of establishing that the reference discloses 
applicant’s invention are properly filed under 37 CFR 
1.132, rather than 37 CFR 1.131, such affidavits submitted 
improperly under 37 CFR 1.131 will be considered 
as though they were filed under 37 CFR 1.132to traverse a ground of rejection. In re Facius, 
408 
F.2d 1396, 161 
USPQ 294 (CCPA 1969).




 

715.01(b)Reference and Application 
Have Common Assignee 

The mere fact that the reference patent or application 
publication which shows but does not claim certain 
subject matter and the application which claims it 
are owned by the same assignee does not avoid the 
necessity of filing an affidavit or declaration under 
37 
CFR 1.131, in the absence of a showing under 
37 
CFR 1.132 that the patentee derived the subject 
matter relied on from the applicant (MPEP § 716.10). 
The common assignee does not obtain any rights in 
this regard by virtue of common ownership which he 
or she would not have in the absence of common 
ownership. In re Frilette, 412 F.2d 269, 162 USPQ 
163 (CCPA 1969); Pierce v. Watson, 275 F.2d 890, 
124 USPQ 356 (D.C. Cir. 1960); In re Beck, 155 
F.2d 
398, 69 USPQ 520 (CCPA 1946). Where, however, a 
rejection is applied under 35 U.S.C. 102(f)/103 or 
35 
U.S.C. 102(g)/103, or, in an application filed on or 
after November 29, 1999, under 35 U.S.C. 102(e)/103using the reference, a showing that the invention 
was 
commonly owned, or subject to an obligation of 
assignment to the same person, at the time the later 
invention was made would preclude such a rejection 
or be sufficient to 
overcome such a rejection. See 
MPEP § 706.02(l) and § 706.02(l)(1).

715.01(c)Reference Is Publication of Applicant’s 
Own Invention [R-2]

Unless it is a statutory bar, a rejection based on a 
publication may be overcome by a showing that it was 
published either by applicant himself/herself or on 
his/her behalf. Since such a showing is not made to 
show a date of invention by applicant prior to the date 
of the reference under 37 
CFR 1.131, the limitation in 
35 U.S.C. 104 and in 37 
CFR 1.131(a)(1) that only 
acts which occurred in this country or in a NAFTA or 
WTO member country may be relied on to establish a 
date of invention is not applicable. Ex parte Lemieux, 
115 USPQ 148, 1957 C.D. 47, 725 O.G. 4 (Bd. App. 
1957); Ex parte Powell, 1938 C.D. 15, 489 O.G. 231 
(Bd. App. 1938). See MPEP § 716.10 regarding 37 
CFR 1.132 affidavits submitted to show that the reference 
is a publication of applicant’s own invention.



I. CO-AUTHORSHIP

Where the applicant is one of the co-authors of a 
publication cited against his or her application, he or 
she may overcome the rejection by filing an affidavit 
or declaration under 37 CFR 1.131. Alternatively, the 
applicant may overcome the rejection by filing a specific 
affidavit or declaration under 37 CFR 1.132establishing that the article is describing applicant’s 
own work. An affidavit or declaration by applicant 
alone indicating that applicant is the sole inventor and 
that the others were merely working under his or her 
direction is sufficient to remove the publication as a 
reference under 35 U.S.C. 102(a). In re Katz, 687 F.2d 
450, 215 USPQ 14 (CCPA 1982).



II. DERIVATION

When the unclaimed subject matter of a patent, 
application publication, or other publication is applicant’s 
own invention, a rejection, which is not a statutory 
bar, on that patent or publication may be 
removed by submission of evidence establishing the 
fact that the patentee, applicant of the published application, 
or author derived his or her knowledge of the 
relevant subject matter from applicant. Moreover 
applicant must further show that he or she made the 
invention upon which the relevant disclosure in the 
patent, application publication, or other publication is 
based. In re Mathews, 408 F.2d 1393, 161 USPQ 276 
(CCPA 1969); In re Facius, 408 F.2d 1396, 161 USPQ 
294 (CCPA 1969).

715.01(d)Activities Applied Against the 
Claims

Unless it is a statutory bar, a rejection based on an 
activity showing that the claimed invention was used 
or known prior to the filing date of the application 
may be overcome by an affidavit or declaration under 
37 CFR 1.131 establishing a date of invention prior to 
the date of the activity. Alternatively, the applicant(s) 
may overcome the rejection by filing a specific affidavit 
or declaration under 37 CFR 1.132 showing that 
the activity was performed by the applicant(s).




 

715.02How Much of the Claimed Invention 
Must Be Shown, Including 
the General Rule as to 
Generic Claims [R-2]

The 37 CFR 1.131 affidavit or declaration must 
establish possession of either the whole invention 
claimed or something falling within the claim (such as 
a species of a claimed genus), in the sense that the 
claim as a whole reads on it. In re Tanczyn, 347 F.2d 
830, 146 USPQ 298 (CCPA 1965) (Where applicant 
claims an alloy comprising both nitrogen and molybdenum, 
an affidavit showing applicant made an alloy 
comprising nitrogen but not molybdenum is not sufficient 
under 37 CFR 1.131 to overcome a rejection 
under 35 U.S.C. 103 based on the combined teachings 
of one reference disclosing an alloy comprising nitrogen 
but not molybdenum and a second reference disclosing 
an alloy comprising molybdenum but not 
nitrogen). Note, however, where the differences 
between the claimed invention and the disclosure of 
the reference(s) are so small as to render the claims 
obvious over the reference(s), an affidavit or declaration 
under 37 CFR 1.131 is required to show no more 
than the reference shows. In re Stryker, 435 F.2d 
1340, 168 USPQ 372 (CCPA 1971). In other words, 
where the examiner, in rejecting a claim under 
35 
U.S.C. 103, has treated a claim limitation as being 
an obvious feature or modification of the disclosure of 
the reference(s) relied upon, without citation of a reference 
which teaches such feature or modification, a 
37 CFR 1.131 affidavit or declaration may be sufficient 
to overcome the rejection even if it does not 
show such feature or modification.

Further, a 37 CFR 1.131 affidavit is not insufficient 
merely because it does not show the identical disclosure 
of the reference(s) or the identical subject matter 
involved in the activity relied upon. If the affidavit 
contains facts showing a completion of the invention 
commensurate with the extent of the invention as 
claimed is shown in the reference or activity, the affidavit 
or declaration is sufficient, whether or not it is a 
showing of the identical disclosure of the reference or 
the identical subject matter involved in the activity. 
See In re Wakefield, 422 F.2d 897, 164 USPQ 636 
(CCPA 1970).

Even if applicant’s 37 CFR 1.131 affidavit is not 
fully commensurate with the rejected claim, the applicant 
can still overcome the rejection by showing that 
the differences between the claimed invention and the 
showing under 37 
CFR 1.131 would have been obvious 
to one of ordinary skill in the art, in view of applicant’s 
37 CFR 1.131 evidence, prior to the effective 
date of the reference(s) or the activity. Such evidence 
is sufficient because applicant’s possession of what is 
shown carries with it possession of variations and 
adaptations which would have been obvious, at the 
same time, to one of ordinary skill in the art. However, 
the affidavit or declaration showing must still 
establish possession of the invention (i.e., the basic 
inventive concept) and not just of what one reference 
(in a combination of applied references) happens to 
show, if that reference does not itself teach the basic 
inventive concept. In re Spiller, 500 F.2d 1170, 
182 
USPQ 614 (CCPA 1974) (Claimed invention 
was 
use of electrostatic forces to adhere dry starch 
particles to a wet paper web on the Fourdrinier wire of 
a paper-making machine. 37 CFR 1.131 affidavit 
established use of electrostatic forces to adhere starch 
particles to wet blotting paper moved over a fluidized 
bed of starch particles prior to the applied reference 
date. Affidavit was sufficient in view of prior art reference 
showing that deposition of dry coatings 
directly on wet webs on the Fourdrinier wire of a 
paper-making machine was well known in the art 
prior to the date of the applied reference. The affidavit 
established possession of the basic invention, i.e., use 
of electrostatic forces to adhere starch to wet paper.).



I. SWEARING BEHIND ONE OF A PLURALITY 
OF COMBINED REFERENCES

Applicant may overcome a 35 U.S.C. 103 rejection 
based on a combination of references by showing 
completion of the invention by applicant prior to the 
effective date of any of the references; applicant need 
not antedate the reference with the earliest filing date. 
However, as discussed above, applicant’s 37 CFR 
1.131 affidavit must show possession of either the 
whole invention as claimed or something falling 
within the claim(s) prior to the effective date of the 
reference being antedated; it is not enough merely to 
show possession of what the reference happens to 
show if the reference does not teach the basic inventive 
concept.




 

Where a claim has been rejected under 35 U.S.C. 
103 based on Reference A in view of Reference B, 
with the effective date of secondary Reference B 
being earlier than that of Reference A, the applicant 
can rely on the teachings of Reference B to show that 
the differences between what is shown in his or her 
37 
CFR 1.131 affidavit or declaration and the claimed 
invention would have been obvious to one of ordinary 
skill in the art prior to the date of Reference A. However, 
the 37 CFR 1.131 affidavit or declaration must 
still establish possession of the claimed invention, not 
just what Reference A shows, if Reference A does not 
teach the basic inventive concept.



II. GENERAL RULE AS TO GENERIC 
CLAIMS 

A reference or activity applied against generic 
claims may (in most cases) be antedated as to such 
claims by an affidavit or declaration under 37 CFR 
1.131 showing completion of the invention of only a 
single species, within the genus, prior to the effective 
date of the reference or activity (assuming, of course, 
that the reference or activity is not a statutory bar or a 
patent, or an application publication, claiming the 
same invention). See Ex parte Biesecker, 144 USPQ 
129 (Bd. App. 1964). See, also, In re Fong, 
288 
F.2d 
932, 129 
USPQ 264 (CCPA 1961); In re 
Defano, 392 F.2d 280, 157 USPQ 192 (CCPA 1968) 
(distinguishing chemical species of genus compounds 
from embodiments of a single invention). See, however, 
MPEP § 715.03 for practice relative to cases in 
unpredictable arts.

715.03Genus-Species, Practice Relative 
to Cases Where Predictability Is 
in Question [R-2]

Where generic claims have been rejected on a reference 
or activity which discloses a species not antedated 
by the affidavit or declaration, the rejection will 
not ordinarily be withdrawn, subject to the rules set 
forth below, unless the applicant is able to establish 
that he or she was in possession of the generic invention 
prior to the effective date of the reference or 
activity. In other words, the affidavit or declaration 
under 37 
CFR 1.131 must show as much as the minimum 
disclosure required by a patent specification to 
furnish support for a generic claim.



I. REFERENCE OR ACTIVITY DISCLOSES 
SPECIES

A.Species Claim

Where the claim under rejection recites a species 
and the reference or activity discloses the claimed 
species, the rejection can be overcome under 37 CFR 
1.131 directly by showing prior completion of the 
claimed species or indirectly by a showing of prior 
completion of a different species coupled with a 
showing that the claimed species would have been an 
obvious modification of the species completed by 
applicant. See In re Spiller, 500 F.2d 1170, 182 USPQ 
614 (CCPA 1974).

B.Genus Claim

The principle is well established that the disclosure 
of a species in a cited reference is sufficient to prevent 
a later applicant from obtaining a “generic claim.” In 
re Gosteli, 872 F.2d 1008, 10 USPQ2d 1614 (Fed. Cir. 
1989); In re Slayter, 276 F.2d 408, 125 USPQ 345 
(CCPA 1960).

Where the only pertinent disclosure in the reference 
or activity is a single species of the claimed genus, the 
applicant can overcome the rejection directly under 
37 
CFR 1.131 by showing prior possession of the species 
disclosed in the reference or activity. On the other 
hand, a reference or activity which discloses several 
species of a claimed genus can be overcome directly 
under 37 
CFR 1.131 only by a showing that the applicant 
completed, prior to the date of the reference or 
activity, all of the species shown in the reference. In re 
Stempel, 241 
F.2d 755, 113 USPQ 77 (CCPA 1957).

Proof of prior completion of a species different 
from the species of the reference or activity will be 
sufficient to overcome a reference indirectly under 
37 
CFR 1.131 if the species shown in the reference or 
activity would have been obvious in view of the species 
shown to have been made by the applicant. In re 
Clarke, 356 F.2d 987, 148 USPQ 665 (CCPA 1966); 
In re Plumb, 470 F.2d 1403, 176 USPQ 323 (CCPA 
1973); In re Hostettler, 356 F.2d 562, 148 USPQ 514 
(CCPA 1966). Alternatively, if the applicant cannot 
show possession of the species of the reference or
activity in this manner, the applicant may be able to 
antedate the reference or activity indirectly by, for 
example, showing prior completion of one or more 
species which put him or her in possession of the 
claimed genus prior to the reference’s or activity’s 
date. The test is whether the species completed by 
applicant prior to the reference date or the activity’s 
date provided an adequate basis for inferring that the 
invention has generic applicability. In re Plumb, 
470 
F.2d 1403, 176 USPQ 323 (CCPA 1973); In re 
Rainer, 390 F.2d 771, 156 USPQ 334 (CCPA 1968); 
In re Clarke, 356 F.2d 987, 148 USPQ 665 (CCPA 
1966); In re Shokal, 242 F.2d 771, 113 USPQ 283 
(CCPA 1957).

It is not necessary for the affidavit evidence to 
show that the applicant viewed his or her invention as 
encompassing more than the species actually made. 
The test is whether the facts set out in the affidavit are 
such as would persuade one skilled in the art that the 
applicant possessed so much of the invention as is 
shown in the reference or activity. In re Schaub, 
537 
F.2d 509, 190 USPQ 324 (CCPA 1976).

C.Species Versus Embodiments

References or activities which disclose one or more 
embodiments of a single claimed invention, as 
opposed to species of a claimed genus, can be overcome 
by filing a 37 CFR 1.131 affidavit showing 
prior completion of a single embodiment of the invention, 
whether it is the same or a different embodiment 
from that disclosed in the reference or activity. See In 
re Fong, 288 F.2d 932, 129 USPQ 264 (CCPA 1961) 
(Where applicant discloses and claims a washing 
solution comprising a detergent and polyvinylpyrrolidone 
(PVP), with no criticality alleged as to the particular 
detergent used, the PVP being used as a soil-
suspending agent to prevent the redeposition of the 
soil removed, the invention was viewed as the use of 
PVP as a soil-suspending agent in washing with a 
detergent. The disclosure in the reference of the use of 
PVP with two detergents, both of which differed from 
that shown in applicant’s 37 CFR 1.131 affidavit, was 
considered a disclosure of different embodiments of a 
single invention, rather than species of a claimed 
genus); In re Defano, 392 F.2d 280, 157 USPQ 192 
(CCPA 1968).



II. REFERENCE OR ACTIVITY DISCLOSES 
CLAIMED GENUS

In general, where the reference or activity discloses 
the claimed genus, a showing of completion of a single 
species within the genus is sufficient to antedate 
the reference or activity under 37 
CFR 1.131. Ex 
parte Biesecker, 144 USPQ 129 (Bd. App. 1964).

In cases where predictability is in question, on the 
other hand, a showing of prior completion of one or a 
few species within the disclosed genus is generally 
not sufficient to overcome the reference or activity. In 
re Shokal, 242 F.2d 771, 113 
USPQ 283 (CCPA 
1957). The test is whether the species completed by 
applicant prior to the reference date or the date of the 
activity provided an adequate basis for inferring that 
the invention has generic applicability. In re Mantell,
454 F.2d 1398, 172 
USPQ 530 (CCPA 1973); In re 
Rainer, 390 F.2d 771, 156 USPQ 334 (CCPA 1968); 
In re DeFano, 392 F.2d 280, 157 USPQ 192 (CCPA 
1968); In re Clarke, 356 F.2d 987, 148 USPQ 665 
(CCPA 1965). In the case of a small genus such as the 
halogens, which consists of four species, a reduction 
to practice of three, or perhaps even two, species 
might show possession of the generic invention, while 
in the case of a genus comprising hundreds of species, 
reduction to practice of a considerably larger number 
of species would be necessary. In re Shokal, supra. 

It is not necessary for the affidavit evidence to 
show that the applicant viewed his or her invention as 
encompassing more than the species he or she actually 
made. The test is whether the facts set out in the 
affidavit are such as would persuade one skilled in the 
art that the applicant possessed so much of the invention 
as is shown in the reference. In re Schaub, 537 F. 
509, 190 USPQ 324 (CCPA 1976).

715.04Who May Make Affidavit or 
Declaration; Formal Requirements 
of Affidavits and Declarations 
[R-5]

I.WHO MAY MAKE AFFIDAVIT OR 
DECLARATION

The following parties may make an affidavit or 
declaration under 37 CFR 1.131:


(A)All the inventors of the subject matter 
claimed. 

(B)An affidavit or declaration by less than all 
named inventors of an application is accepted where it 
is shown that less than all named inventors of an 
application invented the subject matter of the claim or 
claims under rejection. For example, one of two joint 
inventors is accepted where it is shown that one of the 
joint inventors is the sole inventor of the claim or 
claims under rejection.

(C)If a petition under 37 CFR 1.47 was granted 
or the application was accepted under 37 CFR 1.42 or 
1.43, the affidavit or declaration may be signed by the 
37 CFR 1.47 applicant or the legal representative, 
where appropriate. 

(D)The assignee or other party in interest when it 
is not possible to produce the affidavit or declaration 
of the inventor. Ex parte Foster, 1903 C.D. 213, 
105 
O.G. 261 (Comm’r Pat. 1903).

Affidavits or declarations to overcome a rejection 
of a claim or claims must be made by the inventor or 
inventors of the subject matter of the rejected 
claim(s), a party qualified under 37 CFR 1.42, 1.43, or 
1.47, or the assignee or other party in interest when it 
is not possible to produce the affidavit or declaration 
of the inventor(s). Thus, where all of the named 
inventors of a pending application are not inventors of 
every claim of the application, any affidavit under 
37 
CFR 1.131 could be signed by only the inventor(s) 
of the subject matter of the rejected claims. 

II.FORMAL REQUIREMENTS OF AFFIDAVITS 
AND DECLARATIONS

An affidavit is a statement in writing made under 
oath before a notary public, magistrate, or officer 
authorized to administer oaths. See MPEP § 604through § 604.06 for additional information regarding 
formal requirements of affidavits.

37 CFR 1.68 permits a declaration to be used 
instead of an affidavit. The declaration must include 
an acknowledgment by the declarant that willful false 
statements and the like are punishable by fine or 
imprisonment, or both (18 
U.S.C. 1001) and may 
jeopardize the validity of the application or any patent 
issuing thereon. The declarant must set forth in the 
body of the declaration that all statements made of the 
declarant’s own knowledge are true and that all statements 
made on information and belief are believed to 
be true.

715.05U.S. Patent or Application Publication 
Claiming Same Invention[R-5]

When the reference in question is a noncommonly 
owned U.S. patent or patent application 
publication 
claiming the same invention as applicant 
and its publication date is less than 1 year prior to the 
presentation of claims to that invention in the application 
being examined, applicant’s remedy, if any, must 
be by way of 37 CFR 41.202 instead of 37 CFR 1.131. 
If the reference is claiming the same invention as the 
application and its publication date is less than 1 year 
prior to the presentation of claims to that invention in 
the application, this fact should be noted in the Office 
action. The reference can then be overcome only by 
way of interference. See MPEP Chapter 2300. If the 
reference is a U.S. patent which claims the same 
invention as the application and its issue date is more 
than 1 year prior to the presentation of claims to that 
invention in the application, a rejection of the claims 
of the application under 35 U.S.C. 135(b)(1) should 
be made. See In re McGrew, 120 
F.3d 1236, 1238, 43 
USPQ2d 1632, 1635 (Fed. Cir. 1997) (The court holding 
that application of 35 
U.S.C. 135(b) is not limited 
to inter partes interference proceedings, but may be 
used as a basis for ex parte rejections.). The expression 
“prior to one year from the date on which the 
patent was granted” in 35 U.S.C. 135(b) includes the 
one-year anniversary date of the issuance of a patent. 
See Switzer v. Sockman, 333 F.2d 935, 142 USPQ 226 
(CCPA 1964).

If the reference is a U.S. application publication 
under 35 U.S.C. 122(b), or a WIPO publication on an 
international application filed on or after November 
29, 2000, which claims the same invention as the 
application being examined and its publication date is 
more than 1 year prior to the presentation of claims to 
that invention in the application being examined, a 
rejection of the claims of the application (being examined) 
under 35 U.S.C. 135(b)(2) should be made only 
if the application being examined was filed after the 
publication date of the reference.

Form paragraph 23.14 or 23.14.01 may be used 
when making a rejection under 35 U.S.C. 135(b).

¶ 23.14 Claims Not Copied Within One Year of Patent 
Issue Date 

 Claim [l] rejected under 35 U.S.C. 135(b)(1) as not being 
made prior to one year from the date on which U.S. Patent No. [2] 
was granted. See In re McGrew, 120 F.3d 1236, 1238, 43 USPQ2d 
1632, 1635 (Fed. Cir. 1997) where the Court held that 35 U.S.C. 
135(b) may be used as a basis for ex parte rejections.

¶ 23.14.01 Claims Not Copied Within One Year Of 
Application Publication Date 

Claim [l] rejected under 35 U.S.C. 135(b)(2) as not being made 
prior to one year from the date on which [2] was published under 
35 U.S.C. 122(b). See In re McGrew, 120 F.3d 1236, 1238, 43 
USPQ2d 1632, 1635 (Fed. Cir. 1997) where the Court held that 35 
U.S.C. 135(b) may be used as a basis for ex parte rejections.

Examiner Note:

1.In bracket 2, insert the publication number of the published 
application.

2.This form paragraph should only be used if the application 
being examined was filed after the publication date of the published 
application.



Where the reference and the application or 
patent 
under reexamination are commonly owned, 
and the inventions defined by the claims in the application 
or patent under reexamination and by the 
claims in the reference are not identical but are not 
patentably distinct, a terminal disclaimer and an affidavit 
or declaration under 37 CFR 1.130 may be used 
to overcome a rejection under 35 U.S.C. 103. See 
MPEP § 718. 

A 37 CFR 1.131 affidavit is ineffective to overcome 
a United States patent or patent application publication, 
not only where there is a verbatim 
correspondence between claims of the application and 
of the patent, but also where there is no patentable distinction 
between the respective claims. In re Clark, 
457 F.2d 1004, 173 USPQ 359 (CCPA 1972); In re 
Hidy, 303 F.2d 954, 133 USPQ 650 (CCPA 1962); In 
re Teague, 254 F.2d 145, 117 USPQ 284 (CCPA 
1958); In re Ward, 236 F.2d 428, 111 USPQ 101 
(CCPA 1956); In re Wagenhorst, 62 F.2d 831, 
16 
USPQ 126 (CCPA 1933).

If the application (or patent under reexamination) 
and the domestic reference contain claims which are 
identical, or which are not patentably distinct, then the 
application and patent are claiming the “same patentable 
invention.” 

As provided in 37 CFR 41.203(a), an interference 
exists if the subject matter of a claim of one party 
would, if prior art, have anticipated or rendered obvious 
the subject matter of a claim of the opposing party 
and vice versa. An applicant who is claiming an 
invention which is identical to, or obvious in view of, 
the invention as claimed in a 
domestic patent or patent 
application publication cannot employ an affidavit 
under 37 CFR 1.131 as a means for avoiding an interference 
with the reference. To allow an applicant to do 
so would result in the issuance of two patents to the 
same invention.

Since 37 CFR 1.131 defines “same patentable 
invention” in the same way as the interference rules 
(37 CFR 41.203(a)), the USPTO cannot prevent an 
applicant from overcoming a reference by a 37 CFR 
1.131 affidavit or declaration on the grounds that the 
reference claims applicant’s invention and, at the 
same time, deny applicant an interference on the 
grounds that the claims of the application and those of 
the reference are not for substantially the same invention. 
See In re Eickmeyer, 602 F.2d 974, 202 USPQ 
655 (CCPA 1979). Where, in denying an applicant’s 
motion in interference to substitute a broader count, it 
is held that the limitation to be deleted was material 
for the opponent patentee, this constitutes a holding 
that the proposed count is for an invention which is 
not the “same patentable invention” claimed by the 
reference. Therefore, the applicant may file an affidavit 
or declaration under 37 CFR 1.131 to overcome a 
prior art rejection based on the reference. Adler v. Kluver, 
159 USPQ 511 (Bd. Pat. Int. 1968).

Form paragraph 7.58 (reproduced in MPEP § 715) 
may be used to note such a situation in the Office 
action.

715.07Facts and Documentary Evidence 
[R-3]

I.GENERAL REQUIREMENTS

The essential thing to be shown under 37 CFR 
1.131 is priority of invention and this may be done by 
any satisfactory evidence of the fact. FACTS, not conclusions, 
must be alleged. Evidence in the form of 
exhibits may accompany the affidavit or declaration. 
Each exhibit relied upon should be specifically 
referred to in the affidavit or declaration, in terms of 
what it is relied upon to show. For example, the alle





 

gations of fact might be supported by submitting as 
evidence one or more of the following:

(A)attached sketches;

(B)attached blueprints;

(C)attached photographs;

(D)attached reproductions of notebook entries;

(E)an accompanying model;

(F)attached supporting statements by witnesses, 
where verbal disclosures are the evidence relied upon. 
Ex parte Ovshinsky, 10 USPQ2d 1075 (Bd. Pat. App. 
& Inter. 1989);

(G)testimony given in an interference. Where 
interference testimony is used, the applicant must 
point out which parts of the testimony are being relied 
on; examiners cannot be expected to search the entire 
interference record for the evidence. Ex parte Homan, 
1905 C.D. 288 (Comm’r Pat. 1905);

(H)Disclosure documents (MPEP § 1706) may 
be used as documentary evidence of conception.

Exhibits and models must comply with the requirements 
of 37 CFR 1.91 to be entered into an application 
file. See also MPEP § 715.07(d).

A general allegation that the invention was completed 
prior to the date of the reference is not sufficient. 
Ex parte Saunders, 1883 C.D. 23, 23 O.G. 1224 
(Comm’r Pat. 1883). Similarly, a declaration by the 
inventor to the effect that his or her invention was 
conceived or reduced to practice prior to the reference 
date, without a statement of facts demonstrating the 
correctness of this conclusion, is insufficient to satisfy 
37 CFR 1.131.

37 CFR 1.131(b) requires that original exhibits of 
drawings or records, or photocopies thereof, accompany 
and form part of the affidavit or declaration or 
their absence satisfactorily explained. In Ex parte 
Donovan, 1890 C.D. 109, 52 O.G. 309 (Comm’r Pat. 
1890) the court stated 

If the applicant made sketches he should so state, and 
produce and describe them; if the sketches were made and 
lost, and their contents remembered, they should be reproduced 
and furnished in place of the originals. The same 
course should be pursued if the disclosure was by means 
of models. If neither sketches nor models are relied upon, 
but it is claimed that verbal disclosures, sufficiently clear 
to indicate definite conception of the invention, were 
made the witness should state as nearly as possible the 
language used in imparting knowledge of the invention to 
others.

However, when reviewing a 37 CFR 1.131 affidavit 
or declaration, the examiner must consider all of the 
evidence presented in its entirety, including the affidavits 
or declarations and all accompanying exhibits, 
records and “notes.” An accompanying exhibit need 
not support all claimed limitations, provided that any 
missing limitation is supported by the declaration 
itself. Ex parte Ovshinsky, 10 USPQ2d 1075 (Bd. Pat. 
App. & Inter. 1989).

The affidavit or declaration and exhibits must 
clearly explain which facts or data applicant is relying 
on to show completion of his or her invention prior to 
the particular date. Vague and general statements in 
broad terms about what the exhibits describe along 
with a general assertion that the exhibits describe a 
reduction to practice “amounts essentially to mere 
pleading, unsupported by proof or a showing of facts” 
and, thus, does not satisfy the requirements of 37 CFR 
1.131(b). In re Borkowski, 505 F.2d 713, 184 USPQ 
29 (CCPA 1974). Applicant must give a clear explanation 
of the exhibits pointing out exactly what facts 
are established and relied on by applicant. 505 F.2d at 
718-19, 184 USPQ at 33. See also In re Harry, 
333 
F.2d 920, 142 USPQ 164 (CCPA 1964) (Affidavit 
“asserts that facts exist but does not tell what they are 
or when they occurred.”).

II.ESTABLISHMENT OF DATES

If the dates of the exhibits have been removed or 
blocked off, the matter of dates can be taken care of in 
the body of the oath or declaration.

When alleging that conception or a reduction to 
practice occurred prior to the effective date of the reference, 
the dates in the oath or declaration may be the 
actual dates or, if the applicant or patent owner does 
not desire to disclose his or her actual dates, he or she 
may merely allege that the acts referred to occurred 
prior to a specified date. However, the actual dates of 
acts relied on to establish diligence must be provided. 
See MPEP § 715.07(a) regarding the diligence 
requirement.

III.THREE WAYS TO SHOW PRIOR INVENTION


The affidavit or declaration must state FACTS and 
produce such documentary evidence and exhibits in 
support thereof as are available to show conception 
and completion of invention in this country or in 




 

a 
NAFTA or WTO member country (MPEP 
§
 
715.07(c)), at least the conception being at a date 
prior to the effective date of the reference. Where 
there has not been reduction to practice prior to the 
date of the reference, the applicant or patent owner 
must also show diligence in the completion of his or 
her invention from a time just prior to the date of the 
reference continuously up to the date of an actual 
reduction to practice or up to the date of filing his or 
her application (filing constitutes a constructive 
reduction to practice, 37 CFR 1.131).

As discussed above, 37 CFR 1.131(b) provides 
three ways in which an applicant can establish prior 
invention of the claimed subject matter. The showing 
of facts must be sufficient to show:

(A)(actual) reduction to practice of the invention 
prior to the effective date of the reference; or

(B)conception of the invention prior to the effective 
date of the reference coupled with due diligence 
from prior to the reference date to a subsequent 
(actual) reduction to practice; or

(C)conception of the invention prior to the effective 
date of the reference coupled with due diligence 
from prior to the reference date to the filing date of 
the application (constructive reduction to practice).

A conception of an invention, though evidenced by 
disclosure, drawings, and even a model, is not a complete 
invention under the patent laws, and confers no 
rights on an inventor, and has no effect on a subsequently 
granted patent to another, UNLESS THE 
INVENTOR FOLLOWS IT WITH REASONABLE 
DILIGENCE BY SOME OTHER ACT, such as an 
actual reduction to practice or filing an application for 
a patent. Automatic Weighing Mach. Co. v. Pneumatic 
Scale Corp., 166 F.2d 288, 1909 C.D. 498, 139 O.G. 
991 (1st Cir. 1909).

Conception is the mental part of the inventive act, 
but it must be capable of proof, as by drawings, complete 
disclosure to another person, etc. In Mergenthaler 
v. Scudder, 1897 C.D. 724, 81 O.G. 1417 (D.C. 
Cir. 1897), it was established that conception is more 
than a mere vague idea of how to solve a problem; the 
means themselves and their interaction must be comprehended 
also.

In general, proof of actual reduction to practice 
requires a showing that the apparatus actually existed 
and worked for its intended purpose. However, “there 
are some devices so simple that a mere construction 
of them is all that is necessary to constitute reduction 
to practice.” In re Asahi/America Inc., 68 F.3d 442, 37 
USPQ2d 1204, 1206 (Fed. Cir. 1995) (Citing Newkirk 
v. Lulejian, 825 F.2d 1581, 3USPQ2d 1793 (Fed. Cir. 
1987) and Sachs v. Wadsworth, 48 F.2d 928, 929, 9 
USPQ 252, 253 (CCPA 1931). The claimed restraint 
coupling held to 
be so simple a device that mere construction 
of it was sufficient to constitute reduction to 
practice. Photographs, coupled with articles and a 
technical report describing the coupling in detail were 
sufficient to show reduction to practice.).

The facts to be established under 37 CFR 1.131 are 
similar to those to be proved in interference. The difference 
lies in the way in which the evidence is presented. 
If applicant disagrees with a holding that the 
facts are insufficient to overcome the rejection, his or 
her remedy is by appeal from the continued rejection.

See MPEP § 2138.04 through § 2138.06 for a 
detailed discussion of the concepts of conception, reasonable 
diligence, and reduction to practice.

For the most part, the terms “conception,” “reasonable 
diligence,” and “reduction to practice” have the 
same meanings under 37 CFR 1.131 as they have in 
interference proceedings. However, in In re Eickmeyer, 
602 F.2d 974, 202 USPQ 655 (CCPA 1979), the 
court stated: 

The purpose of filing a [37 CFR 1.]131 affidavit is not 
to demonstrate prior invention, per se, but merely to antedate 
the effective date of a reference. See In re Moore, 58 
CCPA 1340, 444 F.2d 572, 170 USPQ 260 (1971). 
Although the test for sufficiency of an affidavit under 
Rule 131(b) parallels that for determining priority of 
invention in an interference under 35 U.S.C. 102(g), it 
does not necessarily follow that Rule 131 practice is controlled 
by interference law. To the contrary, “[t]he parallel 
to interference practice found in Rule 131(b) should be 
recognized as one of convenience rather than necessity.” 
Id. at 1353, 444 F.2d at 580, 170 USPQ at 267. Thus, “the 
‘conception’ and ‘reduction to practice’ which must be 
established under the rule need not be the same as what is 
required in the ‘interference’ sense of those terms.” Id.; 
accord, In re Borkowski, 505 F.2d 713, 718-19, 184 USPQ 
29, 33 (CCPA 1974).

One difference is that in interference practice a 
reduction to practice requires a proof that a utility was 
known, whereas under 37 CFR 1.131 practice, proof 
of a utility must be shown only if the reference discloses 
a utility. In re Wilkinson, 304 F.2d 673, 
134 
USPQ 171 (CCPA 1962); In re Moore, 444 F.2d 




 

572, 170 USPQ 260 (CCPA 1971). Where proof of 
utility is required, whether or not test results are 
required to establish the utility of the subject matter in 
question depends on the facts of each case. The ultimate 
issue is whether the evidence is such that one of 
ordinary skill in the art would be satisfied to a reasonable 
certainty that the subject matter necessary to 
antedate the reference possessed the alleged utility. In 
re Blake, 358 F.2d 750, 149 USPQ 217 (CCPA 1966). 
Also, in interference practice, conception, reasonable 
diligence, and reduction to practice require corroboration, 
whereas averments made in a 37 CFR 1.131 affidavit 
or declaration do not require corroboration; an 
applicant may stand on his or her own affidavit or 
declaration if he or she so elects. Ex parte Hook, 102 
USPQ 130 (Bd. App. 1953).

Form paragraph 7.59 or 7.63 (both reproduced in 
MPEP § 715) may be used where insufficient evidence 
is included in a 37 CFR 1.131 affidavit.

715.07(a)Diligence

Where conception occurs prior to the date of the 
reference, but reduction to practice is afterward, it is 
not enough merely to allege that applicant or patent 
owner had been diligent. Ex parte Hunter, 1889 C.D. 
218, 49 O.G. 733 (Comm’r Pat. 1889). Rather, applicant 
must show evidence of facts establishing diligence.


In determining the sufficiency of a 37 CFR 1.131affidavit or declaration, diligence need not be considered 
unless conception of the invention prior to the 
effective date is clearly established, since diligence 
comes into question only after prior conception is 
established. Ex parte Kantor, 177 USPQ 455 (Bd. 
App. 1958).

What is meant by diligence is brought out in 
Christie v. Seybold, 1893 C.D. 515, 64 O.G. 1650 (6th 
Cir. 1893). In patent law, an inventor is either diligent 
at a given time or he is not diligent; there are no 
degrees of diligence. An applicant may be diligent 
within the meaning of the patent law when he or she is 
doing nothing, if his or her lack of activity is excused. 
Note, however, that the record must set forth an explanation 
or excuse for the inactivity; the USPTO or 
courts will not speculate on possible explanations for 
delay or inactivity. See In re Nelson, 420 F.2d 1079, 
164 USPQ 458 (CCPA 1970). Diligence must be 
judged on the basis of the particular facts in each case. 
See MPEP § 2138.06 for a detailed discussion of the 
diligence requirement for proving prior invention.

Under 37 CFR 1.131, the critical period in 
which 
diligence must be shown begins just prior to 
the effective date of the reference or activity and ends 
with the date of a reduction to practice, either actual 
or constructive (i.e., filing a United States patent 
application). Note, therefore, that only diligence 
before reduction to practice is a material consideration. 
The “lapse of time between the completion or 
reduction to practice of an invention and the filing of 
an application thereon” is not relevant to an affidavit 
or declaration under 37 CFR 1.131. See Ex parte 
Merz, 75 
USPQ 296 (Bd. App. 1947).

Form paragraph 7.62 (reproduced in MPEP § 715) 
may be used to respond to a 37 CFR 1.131 affidavit 
where diligence is lacking.

715.07(b)Interference Testimony Sometimes 
Used 

In place of an affidavit or declaration the testimony 
of the applicant in an interference may be sometimes 
used to antedate a reference in lieu of 37 CFR 1.131affidavit or declaration.

The part of the testimony to form the basis of priority 
over the reference should be pointed out. Ex parte 
Bowyer, 1939 C.D. 5, 42 USPQ 526 (Comm’r Pat. 
1939).

715.07(c)Acts Relied Upon Must Have 
Been Carried Out in This 
Country or a NAFTA or WTO 
Member Country 

35 U.S.C. 104. Invention Made Abroad.

(a)IN GENERAL.—

(1)PROCEEDINGS.—In proceedings in the Patent and 
Trademark Office, in the courts, and before any other competent 
authority, an applicant for a patent, or a patentee, may not establish 
a date of invention by reference to knowledge or use thereof, 
or other activity with respect thereto, in a foreign country other 
than a NAFTA country or a WTO member country, except as provided 
in sections 119 and 365 of this title.

(2)RIGHTS.—If an invention was made by a person, 
civil or military—

(A)while domiciled in the United States, and serving 
in any other country in connection with operations by or on behalf 
of the United States,




 

(B)while domiciled in a NAFTA country and serving 
in another country in connection with operations by or on behalf 
of that NAFTA country, or

(C)while domiciled in a WTO member country and 
serving in another country in connection with operations by or on 
behalf of that WTO member country, that person shall be entitled 
to the same rights of priority in the United States with respect to 
such invention as if such invention had been made in the United 
States, that NAFTA country, or that WTO member country, as the 
case may be.

(3)USE OF INFORMATION.—To the extent that any 
information in a NAFTA country or a WTO member country concerning 
knowledge, use, or other activity relevant to proving or 
disproving a date of invention has not been made available for use 
in a proceeding in the Patent and Trademark Office, a court, or 
any other competent authority to the same extent as such information 
could be made available in the United States, the Director, 
court, or such other authority shall draw appropriate inferences, or 
take other action permitted by statute, rule, or regulation, in favor 
of the party that requested the information in the proceeding.

(b)DEFINITIONS.—As used in this section—

(1)The term “NAFTA country” has the meaning given 
that term in section 2(4) of the North American Free Trade Agreement 
Implementation Act; and

(2)The term “WTO member country” has the meaning 
given that term in section 2(10) of the Uruguay Round Agreements 
Act.

The 37 CFR 1.131 affidavit or declaration must 
contain an allegation that the acts relied upon to establish 
the date prior to the reference or activity were carried 
out in this country or in a NAFTA country or 
WTO member country. See 35 U.S.C. 104.

Under 37 CFR 1.131(a), which provides for the 
establishment of a date of completion of the invention 
in a NAFTA or WTO member country, as well as in 
the United States, an applicant can establish a date of 
completion in a NAFTA member country on or after 
December 8, 1993, the effective date of section 331 of 
Public Law 103-182, the North American Free Trade 
Agreement Act, and can establish a date of completion 
in a WTO member country other than a NAFTA 
member country on or after January 1, 1996, the 
effective date of section 531 of Public Law 103-465, 
the Uruguay Round Agreements Act. Acts occurring 
prior to the effective dates of NAFTA or URAA may 
be relied upon to show completion of the invention; 
however, a date of completion of the 
invention 
may 
not be established under 37 CFR 1.131before December 8, 1993 in a NAFTA country or 
before January 1, 1996 in a WTO country other than a 
NAFTA country. 

715.07(d)Disposition of Exhibits 

Exhibits, such as those filed as part of an affidavit 
or declaration under 37 CFR 1.131, must comply with 
the requirements of 37 CFR 1.91 to be entered into an 
application file. Exhibits that do not comply with the 
requirements of 37 CFR 1.91 will be disposed of or 
returned to applicant at the discretion of the Office. 
See also MPEP § 608.03(a).

715.08Passed Upon by Primary Examiner


The question of sufficiency of affidavits or declarations 
under 37 CFR 1.131 should be reviewed and 
decided by a primary examiner.

Review of questions of formal sufficiency and propriety 
are by petition. Such petitions are answered 
by 
the Technology Center Directors (MPEP 
§
 
1002.02(c)).

Review on the merits of a 37 CFR 1.131 affidavit 
or declaration is by appeal to the Board of Patent 
Appeals and Interferences.

715.09Seasonable Presentation [R-3]

Affidavits or declarations under 37 CFR 1.131 must 
be timely presented in order to be admitted. Affidavits 
and declarations submitted under 37 CFR 1.131 and 
other evidence traversing rejections are considered 
timely if submitted:

(A)prior to a final rejection;

(B)before appeal in an application not having a 
final rejection; 

(C)after final rejection , but before or on the 
same date of filing an appeal, upon a showing of good 
and sufficient reasons why the affidavit or other evidence 
is necessary and was not earlier presented in 
compliance with 37 CFR 1.116(e); or 

(D)after the prosecution is closed (e.g., after a 
final rejection, after appeal, or after allowance) if 
applicant files the affidavit or other evidence with a 
request for continued examination (RCE) under 37 
CFR 1.114 in a utility or plant application filed on or 
after June 8, 1995; or a continued prosecution application 
(CPA) under 37 CFR 1.53(d) in a design application.





 

All admitted affidavits and declarations are 
acknowledged and commented upon by the examiner 
in his or her next succeeding action.

For affidavits or declarations under 37 CFR 1.131filed after appeal, see 37 CFR 41.33(d) and MPEP 
§
 
1206 and §
 
1211.03.

Review of an examiner’s refusal to enter an affidavit 
as untimely is by petition and not by appeal to the 
Board of Patent Appeals and Interferences. In re 
Deters, 515 F.2d 1152, 185 USPQ 644 (CCPA 1975); 
Ex parte Hale, 49 
USPQ 209 (Bd. App. 1941). See 
MPEP § 715.08 regarding review of questions of propriety 
of 37 CFR 1.131 affidavits and declarations.

715.10Review of Affidavit or Declaration 
for Evidence of Prior Public 
Use or Sale or Failure to Disclose 
Best Mode

Any affidavits or declarations submitted under 
37 
CFR 1.131 and the accompanying evidence must 
be reviewed carefully by the examiner in order to 
determine whether they show that the claimed invention 
was “in public use” or “on sale” in this country 
more than one year prior to the effective filing date of 
the application, which acts constitute a statutory bar 
under 35 U.S.C. 102(b). Although the rejection based 
on the reference(s) or activity sought to be antedated 
may actually be overcome by such an affidavit or declaration, 
the effect of the applicant’s prior “public 
use” or “on sale” activities may not be overcome 
under 37 CFR 1.131. See MPEP § 2133.03 regarding 
rejections based on “public use” and “on sale” statutory 
bars.

Where the 37 CFR 1.131 evidence relies on an 
embodiment of the invention not disclosed in the 
application, the question of whether the application 
includes the “best mode” must be considered. However, 
a “best mode” rejection should not be made 
unless the record, taken as a whole, establishes by a 
preponderance of the evidence that applicant's specification 
has not set forth the best mode contemplated by 
the inventor of carrying out the invention. See MPEP 
§ 2165 - § 2165.04 regarding the best mode requirement 
of the first paragraph of 35 U.S.C. 112.