My Software Invention Uses a New Recommendation Algorithm. Which Prior-Art References Should I Review Before Filing?

The short answer: review US and foreign patents and published applications, papers and conference proceedings, preprints and forum posts, public code repositories, product documentation, and your own team’s earlier disclosures, and search each one feature by feature rather than by the name of your algorithm. As a general rule, 35 U.S.C. 102(a)(1) looks at what was already public before the effective filing date, whether patented, described in a printed publication, in public use, on sale or otherwise available to the public, subject to exceptions.¹ That wording can reach online material such as papers, repositories or product documentation, because the MPEP treats an electronic publication, including an online database or Internet publication, as a printed publication if it was accessible to persons concerned with the art.² Whether a particular document qualifies depends on its facts and dates.² Ask counsel about any reference that matters.

One way to start is Patsnap Eureka Novelty Search. You describe the invention, and the Novelty Search Agent pulls out its technical features, runs multiple search strategies and ties each finding to source evidence, leaving the decision about what to file with you.¹¹ Its results are input to your decision, not a finding on patentability or eligibility. Whatever literature the results include, run the non-patent track below yourself as well and add what you find to the same feature table.

The example is hypothetical and names no prior art. Eligibility under 35 U.S.C. 101 is a separate question, so read MPEP 2106 and the USPTO’s July 2024 eligibility update, which includes AI examples, alongside your results.^{8, 9}

1Why software needs two search tracks

What counts as prior art, in general

Section 102(a)(1) is the starting rule: a person is entitled to a patent unless, before the effective filing date, the claimed invention was patented, described in a printed publication, in public use, on sale, or otherwise available to the public.¹ Section 102(a)(2) adds a patent issued under section 151, or an application published or deemed published under section 122(b), that names another inventor and was effectively filed before your effective filing date, subject to the exceptions in 102(b)(2).¹ This guide describes the US rule only.

Documents that are not patents

The MPEP says a reference is considered publicly accessible if it was disseminated or otherwise made available to the extent that persons interested and ordinarily skilled in the subject matter, exercising reasonable diligence, can locate it, and notes that public accessibility has been called the touchstone for a printed publication.² It adds that an electronic publication, including an online database or Internet publication such as a discussion group, forum, digital video or social media post, is a printed publication under 102(a)(1) if it was accessible to persons concerned with the art to which it relates.² That is the general rule behind treating papers, conference proceedings, public code repositories and product documentation as places to look. The same section quotes the Federal Circuit calling the determination a case-by-case inquiry into the facts and circumstances of the disclosure, so a document’s format settles nothing by itself.²

Why patents alone may not be enough

The MPEP tells examiners that in very active, high-technology arts, patent documents may seriously lag behind invention and so be a reference source of limited value, and that examiners in those arts must take special care to include non-patent literature in their searches.³ If your field moves quickly, plan your search the same way. The USPTO’s multi-step search strategy ends with the same step: broaden the search with foreign patents, non-patent literature and/or a patent professional’s search, and search books, journals, websites, technical catalogs and conference proceedings in the applicable field.⁴

2Split the hypothetical invention into features

Search by feature, not by the word “recommendation”. The MPEP ties the analogous-art question to what the claimed subject matter essentially does, not to the name the applicant gives it, and says analogous arts must be searched regardless of where the claimed invention is classified.³ The same function can carry a different name in a paper, a repository and a patent, so give each feature its own vocabulary list.

The vocabulary column is a starting list for your own brainstorming, not a list of the right terms for any real invention.

Collaborative filtering and matrix factorization are useful search words for the representation and scoring rows; they say nothing about what any reference discloses. The USPTO’s strategy begins by brainstorming alternative words for your concept and says to start with a broad keyword search and narrow it by adding features.⁴ Mark the one or two features you believe are new, and search each feature alone and in combination. Keep references that disclose only some features, and ask counsel whether they matter for obviousness under 35 U.S.C. 103.

Build the queries

In Patent Public Search’s Advanced Search, ADJn finds two terms within n terms of each other, in order and in the same sentence, and NEARn does the same in either order; WITHn and SAMEn widen the range to n sentences and n paragraphs.¹³ The USPTO’s efficient-searching guidance advises limited truncation with a small numeric modifier, such as comput$3 for compute and computing, over an open wildcard.¹⁴

Patsnap Eureka Novelty Search starts the same way. The agent picks out claim-like features, their dependencies and the inventive concepts, then maps them to patent claim dimensions for structured searching, and lets you review or edit the extracted features so the search matches your invention.¹¹

3CPC groups to search for the hypothetical recommender

The USPTO’s search strategy says to expand the keyword search with relevant CPC classifications, selecting the CPC system on the Classification Resources page and using a classification search in Patent Public Search’s Advanced Search with the .CPC. field code.⁴ The table lists groups to start from. Titles and warnings are as shown on the USPTO CPC scheme pages, scheme version 2026.08.^{5, 6, 7} Which groups fit your real invention is your judgment, and the “possible fit” column is a search-planning suggestion, not a statement of how any application would be classified.

For each group with a warning, the scheme says all the groups listed in the warning should be considered in order to perform a complete search.^{5, 6, 7} Some of those groups carry warnings of their own, noted in the table. Check the live scheme when you search and note the scheme version in your record. If your recommender does not recommend goods or services, G06Q 30/0631 may not fit; look up the field you actually recommend in, and keep the groups for the learning method.

Include foreign patent documents

Run the patent track on foreign patent documents as well as US ones, and record them. The USPTO’s strategy says to broaden the search with foreign patents and names Espacenet, the European Patent Office’s worldwide patent publication database.⁴

In Patsnap Eureka Novelty Search, the third step expands scope with IPC and CPC codes alongside semantic, keyword, and family and citation strategies, and you can adjust terms or classifications with your domain knowledge.¹¹ Bring the groups above to that checkpoint.

Why run a classification pass

The MPEP tells examiners that text search can work well when terminology is settled, yet a text search alone is rarely a thorough search of patent documents; some mix of text and other criteria, such as classification, would be a normal expectation in most technologies.³ It also says the field of search normally includes the classification locations where the claimed subject matter would be properly classified, and that the examiner should note every CPC group or subgroup that may hold pertinent material and extend the search to all probable areas.³

For software, consider a classification pass next to the keyword pass: a feature is named by whoever wrote the document, so a second route to the same documents that does not depend on wording is worth having. The USPTO’s steps pair the two, then review the references cited by the documents you found and the documents that cite them, which Patent Public Search can search in both directions.⁴ Use classes for the patent track. For the non-patent track, rely on the same feature vocabulary rather than CPC groups.

4The non-patent track: what to review and what to keep

Where to look

• Papers and conference proceedings. The USPTO names journals and conference proceedings as places to search in the applicable field.⁴ Search each of the six features, then follow the references a good hit cites.
• Preprints, forums and posts. The MPEP lists discussion groups, forums, digital video and social media posts among Internet publications that can be printed publications if accessible to persons concerned with the art.²
• Open-source repositories. Read the README, documentation, release notes and history, not only the code. Whether a repository was publicly accessible on a given date is a legal conclusion that turns on the facts, so keep the evidence.²
• Product documentation and technical pages. The USPTO names websites and technical catalogs as sources.⁴ Capture the version you read, since pages change.

Capture the date and the copy

The MPEP says an electronic publication is treated as publicly available as of the date it was publicly posted, and that if a publication carries no publication date or retrieval date and there is no other evidence of the posting date, it cannot be relied on as prior art under 102(a)(1), though it may be relied on as evidence of the state of the art.² It also says Office copies of electronic documents must be retained when the document may not be available later, especially for sources from the Internet and online databases.² Do the same: save the page or file, the URL, the version, the date shown, how you found out when it went public, and the date you retrieved it.

On dating, the MPEP cites a Federal Circuit decision that relied on the Wayback Machine to establish a date of publication, and says publications obtained through it are prima facie deemed publicly accessible at the date and time in the time stamp.² For social media and public forum posts, it says accessibility is decided case by case, considering where the information is posted, privacy restrictions on the posting, the length of time it was posted, and whether it is indexed for searching, and that timestamps on those sites may need careful scrutiny.² Note those four points for any post you rely on.

Include your own team’s material

Under section 102(b)(1), a disclosure made within the year before the effective filing date does not count as prior art under 102(a)(1) if either of these holds:¹

• the inventor, a joint inventor, or another person who obtained the subject matter directly or indirectly from them made the disclosure; or
• the subject matter had, before that disclosure, been publicly disclosed by the inventor, a joint inventor, or another who obtained it directly or indirectly from them.¹

Both the one-year window and one of those conditions must be met. List your own papers, talks and repositories with their dates, and ask counsel whether the exception applies before relying on it. If you may file outside the US, ask counsel before relying on the 102(b)(1) exception, since other systems treat earlier disclosures differently.

Search without publishing your disclosure

The USPTO’s rule for its own examiners is that Internet searches relating to unpublished applications must be limited to the general state of the art and formulated in a way that protects the confidential proprietary intellectual property.³ Take the same care: use general technical terms in public search boxes, and keep the full disclosure out of them.

5Running the search in Patsnap Eureka Novelty Search

The Novelty Search Agent starts from your description. It extracts the technical features, runs multiple search strategies and maps findings to source evidence, so that you can decide what to file.¹¹

Five steps, with the hypothetical

1. Submit an invention disclosure. Write the technical problem, the solution, its advantages and the implementation details in everyday language, or upload a PDF, image or Office document. The agent takes 200 to 500 words and extracts figures automatically.¹¹ For the hypothetical, the six-part split from section 2 is a ready outline.
2. Extract core technical features. The agent picks out claim-like features, their dependencies and the inventive concepts, then maps them to patent claim dimensions for structured searching. At the checkpoint you review or edit the features so the search matches your invention.¹¹ Check that each of the six parts is present and that the feature you believe is new is marked.
3. Build and run search strategies. Keywords, synonyms, semantic concepts, patent classifications and jurisdictions are expanded. Semantic search matches by meaning, four keyword searches cover synonyms, hypernyms, hyponyms and AI field search, classification and Boolean search expands scope via IPC and CPC codes, and family and citation tracing follows the citation chains of key prior art. At the checkpoint you adjust terms or classifications.¹¹
4. Compare against relevant references. The agent ranks the prior art and lines each reference up against your invention’s features in a comparison table, and every cell links back to the source patent text. At the checkpoint you confirm whether each feature is disclosed, partially disclosed or still novel.¹¹
5. Generate a novelty assessment report. The report covers the closest prior art, novelty risks, evidence gaps and patentability considerations, which your team can use when deciding whether to file, refine or stop.¹¹

What stays with you

Patsnap Eureka Novelty Search is not a complete replacement for human IP professionals. The agent takes on the high-volume searching and analysis, and your IP experts audit what it returns and make the final strategic decision.¹¹ Its results are input to your decision, not a finding on patentability or eligibility. Run the non-patent track from section 4 yourself as well, and add each paper, repository or document you find to your own record.

The free trial lasts 14 days and includes 10,000 trial credits.¹¹

Open Novelty Search in Patsnap Eureka →

6Read the US eligibility guidance alongside the search

MPEP 2106

MPEP 2106 states two criteria. The claimed invention must be to one of the four statutory categories, and it must qualify as patent-eligible subject matter, meaning the claim must not be directed to a judicial exception unless the claim as a whole includes additional limitations amounting to significantly more than the exception. The judicial exceptions are limited to abstract ideas, laws of nature and natural phenomena.⁸ The same section adds that involving a judicial exception does not by itself make an invention ineligible, and that a complete examination should be made under the other patentability requirements, including 102 and 103, whether or not a rejection under 101 is made.⁸

The July 2024 guidance update

The USPTO published “2024 Guidance Update on Patent Subject Matter Eligibility, Including on Artificial Intelligence” in the Federal Register on July 17, 2024 (89 Fed. Reg. 58128), effective that day.⁹ The notice says it is meant to help USPTO personnel and stakeholders evaluate the eligibility of claims involving AI inventions, and that it is to be used together with the MPEP.⁹ According to the notice, the existing eligibility guidance in MPEP 2103 to 2106.07(c) is used for all technologies, including AI inventions, which it describes as generally considered computer-implemented inventions.⁹

The notice describes Step 2A as a two-pronged inquiry: whether a claim recites an abstract idea or other judicial exception (Prong One), and, if so, whether the claim as a whole integrates it into a practical application (Prong Two).⁹ It identifies two areas of particular stakeholder concern for AI inventions, the evaluation of whether a claim recites an abstract idea (mathematical concepts, certain methods of organizing human activity and mental processes) and the evaluation of improvements at Prong Two, and it states that an improvement in the judicial exception itself is not an improvement in the technology.⁹ It also announces Examples 47 to 49: hypothetical claims on an artificial neural network used to identify or detect anomalies, on analyzing and separating speech signals, and on an AI model that assists in personalizing medical treatment.⁹ Read the examples on the USPTO site rather than relying on a summary.

The notice says it is not intended to announce any new USPTO practice or procedure, and that it does not constitute substantive rulemaking or have the force and effect of law. It also says that where earlier USPTO guidance, including any section of the current MPEP, is inconsistent with it, USPTO personnel are to follow this guidance.⁹ This guide does not predict how any claim would be treated.

Later USPTO materials

The USPTO’s eligibility page lists the 2024 update as effective July 17, 2024, and says current eligibility guidance is found in MPEP 2103 through 2106.07.¹⁰ It also lists later items, including:

• “Reminders on evaluating subject matter eligibility of claims under 35 U.S.C. 101” (August 4, 2025)¹⁰
• “Advance notice of change to the MPEP in light of Ex Parte Desjardins” (December 5, 2025)¹⁰
• a memorandum on “Best Practices for Submission of Rule 132 Subject Matter Eligibility Declarations (SMEDs)” (April 30, 2026)¹⁰
• a memorandum on “Subject Matter Eligibility Declarations (SMEDs) under 37 CFR 1.132” with a flowchart and best practices (September 29, 2026)¹⁰

Check that page for what applies when you file.

How this fits with the search

The search and the eligibility review start from the same place: what the disclosure actually describes. Writing the six-part feature split in concrete terms helps both conversations with counsel. Do not read a search result, with or without close references, as an answer on eligibility.

7Record the search

The USPTO says it is important to record the details of your search process, such as the databases you used, the date and time of your search, the keywords you searched, and which patents and published patent applications were retrieved.⁴ For a software invention, extend that record.

• Cut-off date. Before searching, fix your cut-off date (your planned or claimed effective filing date) and note it in the record. Keep US patents and published applications whose effective filing date is earlier even if they were published after it, since section 102(a)(2) counts them.¹
• Patent track. The CPC groups searched, including those named in each scheme warning, the scheme version, and the foreign patent documents covered.^{4, 5, 6, 7} Consider keeping the Patsnap Eureka Novelty Search report and its source-linked comparison table in this record.
• Non-patent track. For each paper, repository or product page: URL, version, the date shown and how its public date was established, the date you retrieved it, and a saved copy.
• Feature table. One row per reference, one column per feature of the six-part split, with the passage that discloses it, or a note that it is absent. Mark each feature as disclosed, partially disclosed or still novel.
• Decisions. The terms and groups you tried, what you excluded and why, and what you plan to do next: file, refine, stop, or commission a professional search.
• Re-run. Re-run the search shortly before filing, since applications filed earlier may have published in the meantime.¹²

The USPTO suggests you may want to hire a registered patent attorney or patent agent to review the search.⁴ A complete record lets that person start from your work.

Questions a search leaves open

• Documents you cannot see yet. Under 102(a)(2), a patent or an application published or deemed published under 122(b) that names another inventor and was effectively filed earlier counts as prior art, subject to the 102(b)(2) exceptions.¹ Under 35 U.S.C. 122, the USPTO keeps applications in confidence and, subject to exceptions, publishes each one promptly after 18 months from the earliest filing date for which a benefit is sought, so a public search will not show an earlier-filed application that is still unpublished.¹²
• Public accessibility and dates. Whether and when a paper, repository or web page became publicly accessible is decided on its facts.²
• Eligibility. It is a separate requirement under 35 U.S.C. 101, analyzed under MPEP 2106 and the guidance described above.^{8, 9}
• The legal conclusion. With Patsnap Eureka Novelty Search, auditing the results and making the final strategic decision stay with your IP experts.¹¹
• Other jurisdictions. This guide covers the US only.

Related reading

• How Can AI Help Evaluate the Patentability of an Invention Disclosure Before Filing?
• What Is the Fastest Way to Do a Patentability Check Before Filing?
• How Does an AI Patent Search Tool Distinguish Relevant Claims From Keyword Matches?

Sources and verification

All pages accessed October 22, 2026.

1. 35 U.S.C. 102, Conditions for patentability; novelty, subsections (a)(1), (a)(2), (b)(1) and (b)(2). law.cornell.edu/uscode/text/35/102
2. USPTO, Manual of Patent Examining Procedure, section 2128, “Printed Publications” as Prior Art [R-01.2024], subsections I and II (electronic publications, date of availability, Wayback Machine, social media). uspto.gov/web/offices/pac/mpep/s2128.html
3. USPTO, Manual of Patent Examining Procedure, section 904, How to Search [R-07.2022], including 904.01(c), 904.02, 904.02(a) and 904.02(c). uspto.gov/web/offices/pac/mpep/s904.html
4. USPTO, Multi-Step U.S. Patent Search Strategy (page last updated May 7, 2024). uspto.gov/patents/search/patent-search-strategy
5. USPTO, CPC Scheme, subclass G06Q, version 2026.08, groups G06Q 30/0631, G06Q 30/0251, G06Q 30/0255 and G06Q 30/0269 and the groups named in the G06Q 30/0631 warning. uspto.gov/web/patents/classification/cpc/html/cpc-G06Q.html
6. USPTO, CPC Scheme, subclass G06F, version 2026.08, groups G06F 16/9535, G06F 16/335, G06F 16/435, G06F 16/635, G06F 16/735 and G06F 16/24578, their parent groups and the groups named in their warnings. uspto.gov/web/patents/classification/cpc/html/cpc-G06F.html
7. USPTO, CPC Scheme, subclass G06N, version 2026.08, groups G06N 3/04, G06N 3/08 and G06N 20/00 and the groups named in their warnings. uspto.gov/web/patents/classification/cpc/html/cpc-G06N.html
8. USPTO, Manual of Patent Examining Procedure, section 2106, Patent Subject Matter Eligibility (revision marker R-10.2019 on the page), subsections I and III. uspto.gov/web/offices/pac/mpep/s2106.html
9. USPTO, 2024 Guidance Update on Patent Subject Matter Eligibility, Including on Artificial Intelligence, 89 Fed. Reg. 58128 (July 17, 2024). govinfo.gov/content/pkg/FR-2024-07-17/html/2024-15377.htm
10. USPTO, Subject matter eligibility (page last updated September 29, 2026). uspto.gov/patents/laws/examination-policy/subject-matter-eligibility
11. Patsnap Eureka, Novelty Search: AI novelty search and prior art analysis, including workflow, FAQ and plans. eureka.patsnap.com/novelty-search
12. 35 U.S.C. 122, Confidential status of applications; publication of patent applications, subsections (a), (b)(1) and (b)(2). law.cornell.edu/uscode/text/35/122
13. USPTO, Patent Public Search: Operators (page last updated February 25, 2025). uspto.gov/patents/search/patent-public-search/operators
14. USPTO, Patent Public Search: Efficient searching (page last updated September 29, 2025). uspto.gov/patents/search/patent-public-search/efficient-searching