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Living timeline·Tech industry

HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E

Updated Sep 9, 2026 · 24 dated entries · 25 sources from SK hynix Newsroom, SK hynix, Micron, Samsung Semiconductor and 7 more

Edited by Ceniy Mei · How this page is made

Tech industryHBMMemoryMicronSamsungSK hynix

Chips, illustrating HBM Supply Race: SK hynix, Samsung and Micron from HBM3E to HBM4E
Photo by Liam Briese on Unsplash
TL;DR

The race began with Micron and SK hynix entering HBM3E volume production in early 2024, while Samsung sampled a higher-capacity HBM3E product but did not secure a first-wave Nvidia position. JEDEC published the HBM4 standard in April 2025, but Nvidia’s later Rubin specification change pushed the expected HBM4 production window into the end of the first quarter of 2026. Samsung and Micron announced HBM4 commercial or volume shipments in early 2026, and SK hynix said it began mass HBM4 shipments in the second quarter; all three have now moved into HBM4E, with Samsung and SK hynix shipping samples and Micron targeting volume production in 2027. The central tension is whether suppliers can qualify faster, meet changing customer performance requirements, and expand constrained HBM and advanced-packaging capacity while much of 2026 supply is already committed.

Key moments

12 entries that carry the story, oldest first. The full timeline follows.

  1. Feb 26, 2024Micron starts volume production of HBM3E for Nvidia's H200
  2. Mar 19, 2024SK hynix begins volume production of HBM3E, supplying a customer from late March
  3. Apr 24, 2024SK hynix to build the M15X fab in Cheongju for HBM, about 5.3 trillion won, complete by November 2025
  4. Apr 16, 2025JEDEC publishes the HBM4 standard, doubling channels per stack to 32
  5. Dec 17, 2025Micron completes 2026 HBM price-and-volume agreements
  6. Jan 8, 2026TrendForce: HBM4 mass production slips to the end of the first quarter of 2026 after Nvidia raised the spec
  7. Feb 12, 2026Samsung begins HBM4 mass production and commercial shipments, expects HBM sales to more than triple in 2026
  8. Mar 16, 2026Micron in volume shipment of HBM4 for Nvidia Vera Rubin
  9. May 29, 2026Samsung ships the first 12-layer HBM4E samples at up to 16 Gbps
  10. Jun 18, 2026SK hynix ships 12-layer HBM4E samples to major customers
  11. Jun 24, 2026Micron expects HBM4E volume production in 2027
  12. Jul 29, 2026SK hynix says it began mass shipments of HBM4 in Q2 2026

Timeline

20252026Feb 2024Aug 2026TodayFeb 26, 2024: Micron starts volume production of HBM3E for Nvidia's H200Feb 27, 2024: Samsung develops the first 12-high 36GB HBM3E, mass production planned for the first half of 2024Mar 19, 2024: SK hynix begins volume production of HBM3E, supplying a customer from late MarchApr 3, 2024: SK hynix commits US$3.87 billion to an HBM packaging plant in IndianaApr 24, 2024: SK hynix to build the M15X fab in Cheongju for HBM, about 5.3 trillion won, complete by November 2025Aug 6, 2024: Commerce offers SK hynix up to US$450 million in CHIPS funding for the Indiana plantSep 26, 2024: SK hynix starts mass production of the first 12-layer 36GB HBM3EMar 19, 2025: SK hynix ships the first 12-layer HBM4 samples, targets mass-production readiness in the second half of 2025Mar 20, 2025: Micron begins volume production of 12-high HBM3EApr 16, 2025: JEDEC publishes the HBM4 standard, doubling channels per stack to 32Jun 10, 2025: Micron ships HBM4 36GB 12-high samples, plans the ramp for calendar 2026Jun 12, 2025: Micron says its 36GB 12-high HBM3E is qualified on AI platformsSep 12, 2025: SK hynix completes HBM4 development and says its mass-production system is readySep 24, 2025: Counterpoint reports SK hynix and Samsung held 79% of Q2 HBM shipmentsDec 17, 2025: Micron completes 2026 HBM price-and-volume agreementsJan 8, 2026: TrendForce: HBM4 mass production slips to the end of the first quarter of 2026 after Nvidia raised the specFeb 12, 2026: Samsung begins HBM4 mass production and commercial shipments, expects HBM sales to more than triple in 2026Mar 16, 2026: Micron in volume shipment of HBM4 for Nvidia Vera RubinMar 16, 2026: Samsung shows HBM4 in mass production for Vera Rubin and unveils HBM4E at GTC 2026May 29, 2026: Samsung ships the first 12-layer HBM4E samples at up to 16 GbpsJun 18, 2026: SK hynix ships 12-layer HBM4E samples to major customersJun 24, 2026: Micron expects HBM4E volume production in 2027Jul 29, 2026: SK hynix says it began mass shipments of HBM4 in Q2 2026Aug 27, 2026: SK hynix breaks ground on the Indiana HBM packaging plant, now over US$4 billion with production in 2029
24 entriesbusiest year 2026 (9)Announcements and launchesLegal and regulatoryFinancial and reportskey momentcause, response or contradiction

Earlier years show only their entries' dates and titles. Click a year heading to show the details.

20269 entries
  1. Announcement

    SK hynix breaks ground on the Indiana HBM packaging plant, now over US$4 billion with production in 2029

    SK hynix held the groundbreaking ceremony for its West Lafayette, Indiana advanced packaging plant at Purdue University. The expected investment rose to over US$4 billion, the cleanroom is due by October 2028 and mass production of next-generation HBM in the second half of 2029, a year later than the 2028 target given in April 2024.

    • SK hynix Newsroom · Aug 28, 2026 · The Indiana fab, with a total expected investment of over $4 billion, is scheduled to open its cleanroom by October 2028 and initiate mass production of next-generation HBM in the second half of 2029.

    contradicts SK hynix commits US$3.87 billion to an HBM packaging plant in Indiana.

    Editor's note: Quotes confirmed on the SK hynix newsroom release dated August 28, 2026; the ceremony was on the 27th local time.

  2. ShipmentKey moment

    SK hynix says it began mass shipments of HBM4 in Q2 2026

    SK hynix said it began mass shipments of HBM4 in the second quarter of 2026. It said it would ramp production in the second half of the year.

    • SK hynix · Jul 29, 2026 · The company began mass shipments of HBM4 in the second quarter and will ramp up production in the second half of the year.

    Editor's note: The page states that SK hynix began mass shipments of HBM4 in the second quarter and would ramp up production in the second half of 2026. The release is dated July 29, 2026.

  3. FinancialKey moment

    Micron expects HBM4E volume production in 2027

    Micron said development of HBM4E using 1-gamma DRAM technology was underway. The company said it expected volume production in calendar 2027.

    • Micron · Jun 24, 2026 · Development of HBM4E, built on 1-gamma DRAM technology, is well underway, with volume production expected in calendar 2027.

    Editor's note: The page, published June 24, 2026, states that development of HBM4E built on 1-gamma DRAM technology is well underway and that volume production is expected in calendar 2027.

  4. ShipmentKey moment

    SK hynix ships 12-layer HBM4E samples to major customers

    SK hynix announced that it had shipped HBM4E samples to major customers. The samples were for a 12-layer HBM4E product.

    • SK hynix · Jun 18, 2026 · SK hynix announced today that it has shipped samples of HBM4E, a next-generation DRAM for AI, to major customers.

    Editor's note: The page states that SK hynix shipped HBM4E samples to major customers and specifies that the samples were of a 12-stack (12-layer) HBM4E product. It is dated June 18, 2026, and the quoted sentence appears on the page.

  5. AnnouncementKey moment

    Samsung ships the first 12-layer HBM4E samples at up to 16 Gbps

    Samsung ships the first 12-layer HBM4E samples at up to 16 Gbps
    Image: Samsung Electronics · source

    Samsung said it had begun shipping 12-layer HBM4E samples to major customers, reaching up to 16 Gbps with better energy efficiency and thermals, extending its roadmap after the HBM4 mass production earlier in the year.

    • Samsung Semiconductor · May 29, 2026 · Samsung Electronics, a global leader in advanced memory technology, today announced that it has begun shipping the industry’s first 12-layer HBM4E samples to major global customers, further strengthening its leadership in the next-generation HBM market.
  6. Announcement

    Samsung shows HBM4 in mass production for Vera Rubin and unveils HBM4E at GTC 2026

    Samsung shows HBM4 in mass production for Vera Rubin and unveils HBM4E at GTC 2026
    Image: Samsung Electronics · source

    At Nvidia's GTC 2026 Samsung made its sixth-generation HBM4, in mass production and designed for the Vera Rubin platform, the centerpiece of its showcase and unveiled HBM4E, positioning itself as a Nvidia supplier after missing the first HBM3E wave.

    • Samsung Semiconductor · Mar 16, 2026 · The centerpiece of Samsung’s showcase at NVIDIA GTC 2026 will be the new sixth-generation HBM4, which is now in mass production and is designed for the NVIDIA Vera Rubin platform.
  7. LaunchKey moment

    Micron in volume shipment of HBM4 for Nvidia Vera Rubin

    Micron said it had begun volume shipment of HBM4 36GB 12-high in the first quarter of calendar 2026, designed for Nvidia's Vera Rubin platform, with a 2048-bit interface above 11 Gbps and more than 2.8 TB/s per stack.

    • Micron Investor Relations · Mar 16, 2026 · Micron Technology, Inc. (Nasdaq: MU), has begun volume shipment of its HBM4 36GB 12H in the first quarter of calendar year 2026
  8. LaunchKey moment

    Samsung begins HBM4 mass production and commercial shipments, expects HBM sales to more than triple in 2026

    Samsung begins HBM4 mass production and commercial shipments, expects HBM sales to more than triple in 2026
    Image: Samsung Electronics · source

    Samsung announced mass production and commercial shipment of HBM4 running at 11.7 Gbps and capable of up to 13 Gbps, on a 4nm logic base die, and said it expected its HBM sales to more than triple in 2026 while expanding HBM4 capacity. It was Samsung's first claim of an HBM generation lead over SK hynix.

    • Samsung Semiconductor · Feb 12, 2026 · Samsung anticipates that its HBM sales will more than triple in 2026 compared to 2025, and is proactively expanding its HBM4 production capacity.
    • Samsung Global Newsroom · Feb 12, 2026 · Samsung Electronics, a global leader in advanced memory technology, today announced that it has begun mass production of its industry-leading HBM4 and has shipped commercial products to customers.

    Editor's note: Date from the Samsung Global Newsroom post (meta date 2026-02-12T15:00+09:00), checked in the editor's browser; the Samsung Semiconductor mirror carries a later modification date.

  9. ReportKey moment

    TrendForce: HBM4 mass production slips to the end of the first quarter of 2026 after Nvidia raised the spec

    TrendForce said HBM4 mass production was now expected no earlier than the end of the first quarter of 2026, because Nvidia had revised the HBM4 specification for Rubin in the third quarter of 2025 to a per-pin speed above 11 Gbps, forcing all three suppliers to modify designs, and because strong Blackwell demand led Nvidia to adjust the Rubin production timeline.

    • TrendForce · Jan 8, 2026 · Nvidia has revised the HBM4 specifications for its Rubin platform in 3Q25, raising the required per-pin speed to above 11 Gbps. This change has necessitated that the three major HBM suppliers modify their designs.

    contradicts SK hynix completes HBM4 development and says its mass-production system is ready.

20258 entries
  1. FinancialKey moment

    Micron completes 2026 HBM price-and-volume agreements

    Micron said it had completed price-and-volume agreements for its entire calendar-2026 HBM supply. The agreements included its HBM4 supply.

    Editor's note: The page states that Micron had completed agreements on price and volume for its entire calendar-2026 HBM supply, including HBM4. The page is dated Dec. 17, 2025.

  2. Report

    Counterpoint reports SK hynix and Samsung held 79% of Q2 HBM shipments

    Counterpoint Research reported that SK hynix held 62% and Samsung Electronics held 17% of global HBM shipment share in the second quarter of 2025. The reported combined share was about 79%.

    • Counterpoint Research · 2025년 2분기 전세계 HBM 시장에서 SK하이닉스와 삼성전자가 출하량 기준 점유율 62%, 17%를 기록하며, 이로써 K-HBM이 전체 시장의 약 79% 차지

    Editor's note: Date corrected from 2025-06 to 2025-09-24. The page explicitly states that SK hynix and Samsung Electronics held 62% and 17%, respectively, of global Q2 2025 HBM shipments, totaling about 79%. However, the article was published on 2025-09-24, not in 2025-06.

  3. Announcement

    SK hynix completes HBM4 development and says its mass-production system is ready

    SK hynix announced it had completed HBM4 development and finished preparing mass production, the first supplier to claim both, on the schedule it set in March.

    • SK hynix Newsroom · Sep 12, 2025 · SK hynix Inc. announced today that it has completed development and finished preparation of HBM4, a next generation memory product for ultra-high performance AI, mass production for the world's first time.

    is contradicted by TrendForce: HBM4 mass production slips to the end of the first quarter of 2026 after Nvidia raised the spec.

  4. Shipment

    Micron says its 36GB 12-high HBM3E is qualified on AI platforms

    Micron said its 36GB 12-high HBM3E product was qualified on multiple leading AI platforms. The statement did not identify the platforms in the quoted sentence.

    • Micron · Jun 12, 2025 · Micron HBM3E 36GB 12-high product is now qualified on multiple leading AI platforms.

    Editor's note: The page is readable and is dated June 12, 2025. It states verbatim that Micron's HBM3E 36GB 12-high product is qualified on multiple leading AI platforms, without identifying those platforms in that sentence.

  5. Announcement

    Micron ships HBM4 36GB 12-high samples, plans the ramp for calendar 2026

    Micron announced shipment of HBM4 36GB 12-high samples to multiple key customers and said it planned to ramp HBM4 in calendar 2026 in line with customers' next-generation AI platforms.

    • Micron Investor Relations · Jun 10, 2025 · Micron plans to ramp HBM4 in calendar year 2026, aligned to the ramp of customers' next-generation AI platforms.
  6. AnnouncementKey moment

    JEDEC publishes the HBM4 standard, doubling channels per stack to 32

    JEDEC released JESD270-4, the HBM4 standard, which doubles independent channels per stack from 16 to 32 with two pseudo-channels each, keeps backward compatibility with HBM3 controllers and adds directed refresh management. SK hynix, AMD, Synopsys and Cadence gave statements.

    • JEDEC · Apr 16, 2025 · Doubled Channels: HBM4 doubles the number of independent channels per stack, from 16 channels (HBM3) to 32 channels with 2 pseudo-channels per channel.
  7. Launch

    Micron begins volume production of 12-high HBM3E

    Micron said it had begun volume production of 12-high HBM3E. The company said it was focused on ramping capacity and yield.

    Editor's note: The page’s prepared remarks state that Micron had begun volume production of HBM3E 12-high and was focused on ramping capacity and yield. The transcript is dated March 20, 2025, matching the node date.

  8. Announcement

    SK hynix ships the first 12-layer HBM4 samples, targets mass-production readiness in the second half of 2025

    SK hynix said it had shipped 12-layer HBM4 samples to major customers, the first supplier to do so, and aimed to complete mass-production preparations within the second half of 2025.

    • SK hynix Newsroom · Mar 19, 2025 · SK hynix aims to complete preparations for mass production of 12-layer HBM4 products within the second half of the year.
  1. Dec 17, 2025Micron completes 2026 HBM price-and-volume agreements
  2. Sep 24, 2025Counterpoint reports SK hynix and Samsung held 79% of Q2 HBM shipments
  3. Sep 12, 2025SK hynix completes HBM4 development and says its mass-production system is ready
  4. Jun 12, 2025Micron says its 36GB 12-high HBM3E is qualified on AI platforms
  5. Jun 10, 2025Micron ships HBM4 36GB 12-high samples, plans the ramp for calendar 2026
  6. Apr 16, 2025JEDEC publishes the HBM4 standard, doubling channels per stack to 32
  7. Mar 20, 2025Micron begins volume production of 12-high HBM3E
  8. Mar 19, 2025SK hynix ships the first 12-layer HBM4 samples, targets mass-production readiness in the second half of 2025
20247 entries
  1. Launch

    SK hynix starts mass production of the first 12-layer 36GB HBM3E

    SK hynix said it had begun mass production of the world's first 12-layer HBM3E with 36GB, running at 9.6 Gbps, with 3GB dies each 40 percent thinner than before, and planned to supply the product to customers within the year.

    • SK hynix Newsroom · Sep 26, 2024 · The company plans to supply mass-produced products to customers within the year

    Editor's note: Quote confirmed on the SK hynix newsroom release dated September 26, 2024.

  2. Regulatory

    Commerce offers SK hynix up to US$450 million in CHIPS funding for the Indiana plant

    SK hynix signed a non-binding preliminary memorandum of terms with the U.S. Department of Commerce for up to US$450 million in proposed direct funding and US$500 million in loans under the CHIPS and Science Act for the Indiana packaging facility.

    • SK hynix Newsroom · Aug 6, 2024 · SK hynix Inc. announced today it has signed a non-binding preliminary memorandum of terms with the U.S. Department of Commerce to receive up to $450 million in proposed direct funding and access to proposed loans of $500 million as part of the CHIPS and Science Act
  3. AnnouncementKey moment

    SK hynix to build the M15X fab in Cheongju for HBM, about 5.3 trillion won, complete by November 2025

    SK hynix said it would invest about 5.3 trillion won to build M15X in Cheongju as a new DRAM base focused on HBM, targeting completion in November 2025 for early mass production, next to the M15 plant where TSV capacity was being expanded.

    • SK hynix Newsroom · Apr 24, 2024 · increasing DRAM capabilities with a focus on HBM is a precondition for future growth.
  4. Announcement

    SK hynix commits US$3.87 billion to an HBM packaging plant in Indiana

    SK hynix signed an agreement with the state of Indiana to build an advanced packaging and R&D facility in West Lafayette for AI memory, with mass production planned for the second half of 2028, the first HBM packaging plant announced in the United States.

    • SK hynix Newsroom · Apr 3, 2024 · The company plans to begin mass production in the second half of 2028

    is contradicted by SK hynix breaks ground on the Indiana HBM packaging plant, now over US$4 billion with production in 2029.

  5. LaunchKey moment

    SK hynix begins volume production of HBM3E, supplying a customer from late March

    SK hynix said it had begun volume production of HBM3E for supply to a customer from late March 2024. It did not name the customer; the announcement came the day after Nvidia's GTC keynote.

    • SK hynix Newsroom · Mar 19, 2024 · SK hynix Inc. announced today that it has begun volume production of HBM3E, the newest AI memory product with ultra-high performance, for supply to a customer from late March.
  6. Announcement

    Samsung develops the first 12-high 36GB HBM3E, mass production planned for the first half of 2024

    Samsung announced HBM3E 12H, a 12-stack, 36GB part it called the highest-capacity HBM to date, said it had begun sampling to customers, and targeted mass production in the first half of 2024.

    • Samsung Semiconductor · Feb 27, 2024 · Samsung has begun sampling its HBM3E 12H to customers and mass production is slated for the first half of this year.
  7. LaunchKey moment

    Micron starts volume production of HBM3E for Nvidia's H200

    Micron said it had begun volume production of its 24GB 8-high HBM3E, which would ship inside Nvidia H200 GPUs from the second calendar quarter of 2024, making Micron a first-wave HBM3E supplier alongside SK hynix.

    • Micron Investor Relations · Feb 26, 2024 · Micron's 24GB 8H HBM3E will be part of NVIDIA H200 Tensor Core GPUs, which will begin shipping in the second calendar quarter of 2024.
  1. Sep 26, 2024SK hynix starts mass production of the first 12-layer 36GB HBM3E
  2. Aug 6, 2024Commerce offers SK hynix up to US$450 million in CHIPS funding for the Indiana plant
  3. Apr 24, 2024SK hynix to build the M15X fab in Cheongju for HBM, about 5.3 trillion won, complete by November 2025
  4. Apr 3, 2024SK hynix commits US$3.87 billion to an HBM packaging plant in Indiana
  5. Mar 19, 2024SK hynix begins volume production of HBM3E, supplying a customer from late March
  6. Feb 27, 2024Samsung develops the first 12-high 36GB HBM3E, mass production planned for the first half of 2024
  7. Feb 26, 2024Micron starts volume production of HBM3E for Nvidia's H200

Cause and effect

  1. SK hynix completes HBM4 development and says its mass-production system is readyis contradicted by →TrendForce: HBM4 mass production slips to the end of the first quarter of 2026 after Nvidia raised the specSK hynix declared mass production ready in September 2025; TrendForce reported the start slipping to late in the first quarter of 2026 after Nvidia raised the per-pin speed.
  2. SK hynix commits US$3.87 billion to an HBM packaging plant in Indianais contradicted by →SK hynix breaks ground on the Indiana HBM packaging plant, now over US$4 billion with production in 2029The April 2024 plan said mass production in the second half of 2028; at the 2026 groundbreaking it became the second half of 2029.

Where sources disagree or fall silent

  • The customer names and qualification status for several HBM4 and HBM4E sample programs remain undisclosed, including SK hynix's major customers and Samsung's HBM4E sample recipients.
  • Samsung calls its February 2026 product the first commercial HBM4 shipment, while Micron says it began HBM4 volume shipments in the first quarter of 2026; the sources do not provide enough detail to directly compare the scale or exact timing of those shipments.
  • SK hynix said in September 2025 that its HBM4 mass-production system was ready, but TrendForce later reported that all suppliers had to revise designs after Nvidia raised the Rubin specification; the extent of the resulting change to SK hynix's original readiness claim is not disclosed.
  • Micron says its full 2026 HBM supply is covered by price-and-volume agreements, but the sources do not disclose the customers, prices, volumes, or how much supply is HBM4 versus earlier HBM products.
  • SK hynix's Indiana plant production target moved from the second half of 2028 to the second half of 2029; the sources identify the revised schedule but do not fully explain the cause of the one-year delay.

What to watch next

Who is involved

  • SK hynixcompany

    An early HBM3E and HBM4 supplier that is expanding DRAM and packaging capacity in Cheongju and Indiana and has shipped HBM4E samples.

  • HBM4product

    The standardized next HBM generation now in commercial or volume shipments from Samsung, Micron and SK hynix.

  • Microncompany

    Third supplier; entered with HBM3E in H200 and volume HBM4 for Vera Rubin.

  • HBM3Eproduct

    The high-bandwidth-memory generation that entered volume production in 2024 and established the initial supplier race for AI accelerators.

  • Samsung Electronicscompany

    A competing memory supplier that announced HBM4 commercial shipments in February 2026 and HBM4E samples in May 2026.

  • Nvidiacompany

    The leading AI-accelerator customer whose H200, Blackwell and Vera Rubin platform schedules and HBM4 specification changes shape supplier timelines.

  • HBM4Eproduct

    The follow-on HBM generation for which Samsung and SK hynix have sent samples, while Micron targets 2027 volume production.

  • HBMproduct

    High-bandwidth-memory category covered by shipment-share and supply-agreement statements.

7 more
  • State of Indianaregulator

    Signed an agreement with SK hynix to build an advanced packaging and R&D facility in West Lafayette.

  • 1-gamma DRAMproduct

    DRAM technology Micron said would underpin HBM4E.

  • AMDcompany

    An AI-platform customer cited in connection with Micron's qualified HBM3E design wins and the HBM4 standard.

  • Counterpoint Researchcompany

    Market research firm that reported SK hynix and Samsung together held about 79% of global HBM shipments in the second quarter of 2025.

  • JEDECother

    The semiconductor standards body that released the JESD270-4 HBM4 standard in April 2025.

  • TrendForceother

    Market research firm that reported the Rubin-related HBM4 schedule delay after Nvidia raised the required per-pin speed.

  • U.S. Department of Commerceregulator

    The agency that offered proposed CHIPS Act funding and loans for SK hynix's Indiana advanced-packaging project.

Changelog

Changes to this timeline. All timelines' changes.

  • Summary, key players and catalysts refreshed.
  • Summary, key players and catalysts refreshed.
  • Added 2 node(s): 2025-03-20 Micron begins volume production of 12-high HBM3E; 2025-12-17 Micron completes 2026 HBM price-and-volume agreements.
  • Summary, key players and catalysts refreshed.
  • Added 7 node(s): 2024-09-26 SK hynix starts mass production of the first 12-layer 36GB HBM3E; 2025-06-12 Micron says its 36GB 12-high HBM3E is qualified on AI platforms; 2025-09-24 Counterpoint reports SK hynix and Samsung held 79% of Q2 HBM shipments; 2026-06-18 SK hynix ships 12-layer HBM4E samples to major customers and 3 more.
  • Research run found 8 candidate node(s).
  • Seeded 15 hand-verified node(s) from hbm-memory-supply.yaml.

A research pass records each dated fact with the page it came from and a verbatim quote. A second, independent pass re-opens every cited page and rejects entries it cannot confirm. The editor reviews what remains before it is published, and every change is listed above. Full method.