The Korean Intellectual Property Office (KIPO) has pursued aggressive patent system modernization in recent years: prohibiting multi-multi-claim dependent claims (다항인용다항) in 2022, introducing the separated application (분리출원) system the same year, and significantly expanding priority examination (우선심사) categories in 2025. These changes have profoundly reshaped Korean patent prosecution (변리사) practice. This guide systematically addresses eight core aspects of Korean patent filing, with particular focus on the latest reforms.

Target readers: Patent attorneys handling KR PCT national phase; IP teams filing for Korean market protection; cross-jurisdictional practitioners understanding JP-KR practice differences.

1. Multi-Multi-Claim Prohibition: April 2022 Effective Date

1.1 Overview

Effective 1 April 2022, Patent Act Article 42, Paragraph 8 explicitly prohibits "multi-multi-claim (다항인용다항)" dependent claims—where a dependent claim references two or more dependent claims.

This amendment is highly synchronized with JPO's simultaneous prohibition of マルチマルチクレーム, reflecting the two countries' coordinated trend toward claim format standardization.

1.2 Non-Compliant Examples

Prohibited scenario (non-compliant after April 2022):

【청구항1】　A wireless communication device comprising a processor and memory.
【청구항2】　The device of claim 1, wherein the processor performs operation A.
【청구항3】　The device of claim 1, wherein the processor performs operation B.
【청구항4】　The device of claim 2 or 3, wherein the memory stores C.
(Claim 4 references Claims 2 and 3, both of which are dependent claims—non-compliant)

Compliant alternative:

【청구항4】　The device of claim 1, wherein the memory stores C.
(Claim 4 references only independent Claim 1—compliant)

1.3 Adaptation Strategies

Previous Approach (pre-2022)	Post-2022 Compliant Restructuring
Multi-level dependent claim tree	Convert intermediate-level dependents to reference independent claims
"Claim N or M" where N, M are both dependent	Create two separate dependent claims, each referencing the independent claim
Combining dependent claims	Add new independent claim or handle through divisional

2. Paragraph Numbers and Document Structure

2.1 Full-Width Bracket Four-Digit Format

Korean Patent Act Enforcement Rules Form 21 (시행규칙 제21조) requires each paragraph of the specification (명세서) to carry a full-width bracket four-digit paragraph number:

Correct: 【0001】　본 발명은 무선 통신 장치에 관한 것이다.
Incorrect: (0001) 본 발명은... (half-width brackets)
Incorrect: 【1】 본 발명은... (fewer than four digits)

2.2 KR Standard Document Structure

Per KIPO requirements, the standard Korean specification structure is:

【발명의 설명】
【기술분야】
【배경기술】
【선행기술문헌】（recommended）
  【특허문헌】
  【비특허문헌】
【발명의 내용】
  【해결하려는 과제】
  【과제의 해결 수단】
  【발명의 효과】
【도면의 간단한 설명】
【발명을 실시하기 위한 구체적인 내용】
【부호의 설명】（recommended）

2.3 JP vs KR Paragraph Number Comparison

Dimension	JP (Form 29)	KR (Enforcement Rules Form 21)
Format	【0001】 (full-width)	【0001】 (full-width, identical)
Claim format	【請求項１】	【청구항 1】
Drawing reference	【図1】	【도 1】
Section headings	【技術分野】 etc. (Japanese)	【기술분야】 etc. (Korean)

3. Korean-English Parallel Notation (한자/영문 병기)

3.1 Legal Basis

KIPO examination guidelines and Korean Patent Act Enforcement Rules require: technical terms in the specification must include Chinese character or English parallel notation (병기) upon first appearance.

Format examples:

반도체(半導體) — Chinese character notation
트랜지스터(transistor) — English notation
인공지능(artificial intelligence, AI) — English notation (with abbreviation)

3.2 Scope of Application

Scenario	Notation Required?
Same term appearing for the first time	Required
Same term appearing again	Not required (noted at first occurrence)
Commonly known general terms	Case-by-case; ordinary vocabulary may be exempt
Abbreviations on first use	Required (full form should also be provided)

3.3 High-Risk Terms: Common Technical Vocabulary Requiring Notation

Korean Term	Recommended Parallel Notation
인공지능	인공지능(artificial intelligence, AI)
딥러닝	딥러닝(deep learning)
반도체	반도체(半導體, semiconductor)
프로세서	프로세서(processor)
알고리즘	알고리즘(algorithm)
데이터베이스	데이터베이스(database)
신경망	신경망(神經網, neural network)

4. Bilingual Title Format for 발명의 명칭

4.1 Mandatory English Title Format

Korean Patent Act Enforcement Rules require that 발명의 명칭 (title of the invention) provide both a Korean title and an English title, with the English title in uppercase letters enclosed in curly braces:

Standard format:

발명의 명칭: 차분 프라이버시 메커니즘을 이용한 무선 통신 장치 및 방법
             {WIRELESS COMMUNICATION DEVICE AND METHOD USING DIFFERENTIAL PRIVACY MECHANISM}

Format requirements:

English title entirely in uppercase
Enclosed in curly braces {} (Korea-specific format)
Placed after the Korean title
English title must correspond to the Korean title in content (meaning must not be altered)

4.2 Comparison with Other Jurisdictions

Jurisdiction	Title Format
KR	Korean + `{ENGLISH UPPERCASE}`
JP	Japanese only (no English required)
EP	English only (or French/German)
US	English only
CN	Chinese only (English appended for PCT national phase)

5. Representative Drawing (대표도): Korea's Unique Mandatory Requirement

5.1 System Description

KIPO requires applicants to designate a 대표도 (Representative Drawing) at the time of filing—the drawing that best represents the core technical features of the invention, used in official gazette announcements, database displays, etc.

This is a unique mandatory requirement for Korean patent applications. JPO, EPO, and USPTO have no equivalent mandatory requirement (EPO selects an abstract drawing, but this is not a mandatory format requirement).

5.2 Representative Drawing Selection Principles

Prioritize drawings that represent the invention's overall structure/process
Should be a clear line drawing (not a photograph)
Avoid selecting detail views or partial enlargements as the 대표도
Explain the 대표도 number in the 【도면의 간단한 설명】 section

Export format requirements: In DOCX export, the representative drawing should be marked with 【대표도】 in the drawings section:

【도면의 간단한 설명】
【도 1】　Block diagram of a wireless communication device according to a preferred embodiment of the present invention (대표도)
【도 2】　...

6. Separated Application vs Divisional Application: The 2022 New System

6.1 Separated Application (분리출원) — New in 2022

In April 2022, Korea introduced the separated application (분리출원) system (Patent Act Article 52-2), a Korea-specific mechanism with no equivalent in JP, EP, or US:

Trigger condition: Within 30 days after the Patent Trial and Appeal Board (특허심판원) issues a rejection decision (심결), the applicant may file a separated application to split out certain claims from the rejected application and continue examination as a new application.

Core distinction from divisional application (분할출원):

Dimension	Separated Application (새 제도)	Divisional Application (traditional)
Trigger timing	Within 30 days after 심판 decision	During examination/re-examination stage (before final rejection)
Trigger condition	Patent Trial and Appeal Board rejection	Applicant's voluntary initiative
Essential nature	Post-rejection relief pathway	Proactive divisional strategy
Priority date retained	Yes (based on original filing date)	Yes (based on original filing date)

6.2 Divisional Application (분할출원) Practice

The traditional divisional (분할출원) mechanism can be filed at:

During response to examination Office Action
At the time of requesting re-examination (재심사 청구)
When filing an appeal against rejection (거절결정불복심판)

Divisional content restriction: Divisional applications cannot introduce new matter not disclosed in the original application (same as Japan's 新規事項禁止 principle).

7. Priority Examination (우선심사): Complete 2025 Category Expansion

7.1 System Overview

KIPO's priority examination (우선심사) system allows qualifying applications to skip the standard examination queue, typically reducing examination time from 24-30 months to approximately 6-12 months.

7.2 Complete List of Categories After 2025 Expansion

On 19 February 2025, KIPO officially expanded 우선심사 eligible categories:

Category	Technical Field	2025 Status
인공지능 (AI)	Machine learning, deep learning, NLP	Pre-existing
바이오기술 (BIO)	Biotechnology, genetic engineering, pharma	Pre-existing
첨단로봇	Advanced robotics	Pre-existing
반도체	Semiconductor manufacturing, chip design	Newly added 2025
디스플레이	Display technology (OLED, micro-LED, etc.)	Newly added 2025
이차전지	Secondary batteries, energy storage	Newly added 2025
수소경제	Hydrogen energy technology	Newly added 2025
탄소중립	Carbon neutrality, clean energy	Newly added 2025
중소기업/벤처기업	Small and medium enterprises, startups	Expanded 2025
조기실시	Invention being or about to be implemented	Pre-existing
PCT 국내단계	PCT national phase applications	Pre-existing
PPH	Patent Prosecution Highway	Pre-existing

7.3 Practice Notes for Priority Examination Applications

Submit a 우선심사신청서 (priority examination application) and pay 우선심사수수료
For 중소기업/벤처기업 category, attach documentation proving enterprise size
For technical field categories (AI, 반도체, etc.), claims must genuinely relate to that technical field (KIPO will verify)
Accelerated examination does not mean lower examination standards—권리범위 and 신규성/진보성 requirements remain unchanged

8. Grace Period (공지예외주장): The 12-Month System and Comparison with US

8.1 Korea's 12-Month Grace Period

Patent Act Article 30 provides: if the inventor (or rights holder) publicly disclosed the invention within 12 months before the filing date for the following reasons, a grace period exception (공지예외) may be claimed:

Inventor's own disclosure (academic publication, conference presentation, product demonstration, etc.)
Unintended disclosure (theft, leak, etc.)

Key comparison with US and EP:

Jurisdiction	Grace Period	Scope
KR	12 months	Inventor's own disclosure + unintended disclosure
US	12 months (35 U.S.C. § 102(b)(1))	Essentially unlimited (including third-party disclosures)
JP	6 months (Patent Act Art. 30)	Narrower (specified disclosures within designated timeframe)
EP	Practically no grace period (EPC Art. 55: only 6-month narrow exception)	Obvious abuse + exhibition disclosure only
CN	6 months	Academic publication, exhibitions, etc.

8.2 Procedure for Claiming Grace Period Exception

Applicants must submit at filing (or within 30 days after filing):

공지예외주장 신청서 (grace period claim application)
관련 증명서류 (relevant supporting documents, such as proof of paper publication, exhibition participation certificate)

Practice note: Korean grace period claims must specifically identify the disclosure act (document, date, occasion). Vague blanket claims are not acceptable. If there are numerous disclosure documents, list each one individually.

9. Patent Prosecution Highway (PPH) Participation

9.1 KIPO's PPH Agreement Network

KIPO has PPH agreements with: USPTO, EPO (as member office), JPO, CNIPA, IP5 members, and others, covering virtually all major markets.

Core requirements for PPH application:

Cooperating office (e.g., USPTO) has issued allowed claims
KR application's corresponding claims must be of equal or narrower scope than the allowed claims
Must submit cooperating office examination documents (search report, OA, Notice of Allowance, etc.)

9.2 Relationship Between PPH and 우선심사

PPH is effectively one triggering pathway for 우선심사. Applications meeting PPH conditions can simultaneously claim both PPH and 우선심사 dual acceleration. In practice, if US/EP allowed claims are already available, applying for KR PPH is one of the most efficient acceleration pathways available.

10. How CNIPA.AI Assists in the Korean Patent Process

Korean patent application format requirements are among the most distinctive of major patent offices—bilingual titles, 대표도, parallel notation, 분리출원 judgment: each requires precise knowledge support. Here are scenarios where AI tools can add value in KR practice:

Format compliance checking:

다항인용다항 automatic detection (flag dependent claim references violating the prohibition)
발명의 명칭 bilingual format verification (check English uppercase format and curly braces)
Paragraph number continuity verification (full-width bracket four-digit format)
한자/영문 병기 omission alerts (scan for unannotated technical terms)

Document structure assistance:

Auto-generate 【선행기술문헌】 section (with 【특허문헌】 and 【비특허문헌】 subsections)
Auto-generate 【부호의 설명】 section (extract symbol list from drawing annotations)
대표도 number verification (check whether 대표도 is explicitly designated in specification)

Procedural reminders:

우선심사 eligibility pre-assessment (based on technical field and applicant type)
심사청구 3-year deadline automatic calculation
분리출원 window reminder (within 30 days after 심결 확정)

These are assistive tools. Precise judgment on 한자/영문 병기, strategic decisions on 분리출원, and final 권리요구 interpretation must be handled by qualified Korean 변리사.

Appendix: Korean Patent Act Key Provisions Quick Reference

Provision	Subject	Core Requirements
특허법 제42조	Patent requirements and specification recording	발명의 설명 and 청구범위 recording requirements
특허법 제42조 제8항	Multi-multi-claim prohibition	Effective 2022-04-01: prohibits multi-multi dependent claim references
특허법 제30조	Grace period exception	Disclosures within 12 months before filing → grace period applies
특허법 제52조	Divisional application	Division possible during examination/re-examination stage
특허법 제52조의2	Separated application	New in 2022: within 30 days after 심결 확정
특허법 제59조	Examination request	Must be filed within 3 years of filing date
특허법 제55조	Priority examination	May be applied for when meeting eligible type criteria
시행규칙 제21조	Specification format	Paragraph numbers 【0001】, bilingual 발명의 명칭

Appendix: 2025 Complete Priority Examination Eligible Technical Field Table

Technical Field	Detailed Content	Status
인공지능 (AI)	ML, DL, NLP, computer vision	Existing
바이오기술	Genetic engineering, stem cells, biosimilars	Existing
첨단로봇	Autonomous robots, collaborative robots	Existing
반도체	Semiconductor process, SoC, packaging	New 2025
디스플레이	OLED, MicroLED, transparent display	New 2025
이차전지	All-solid-state battery, Li-ion, battery management	New 2025
수소경제	Water electrolysis, fuel cells, hydrogen storage	New 2025
탄소중립	Carbon capture, renewable energy, energy efficiency	New 2025
중소기업/벤처기업	SMEs under SME Framework Act, venture enterprises	Expanded 2025

Korean Patent Attorney Deep Dive: From Multi-Multi Claim Prohibition to 2025 Priority Examination Expansion