4.1 Changelog

• Chapter 3.2: Removal of the optional Method 2 for issuance. The Ongoing Issuance option (method 2) with annual balance as defined in General rules 4.0 Appendix A is removed due to CORSIA not considering it eligible. The Model 1 issuance option will be used for all issuances. Please see the Increased Audit Frequency section below for details on a service that replaces our Ongoing Issuance Rights. 
• Chapters 2.2 and 2.3 Amendments to the language related to publicly available information after Production Facility Audit and Output Audit. The information is disseminated as sections in a project description document. 
• Rule 6.4.3.iii inclusion of Environmental and Social Monitoring Plan requirement. 
• Rule 6.7.4 assurances on the responsibility of the supplier to meet its monitoring obligations. 
• Rule 6.7.4.1 (previous § 6.7.5.1) clarification on time the CO2 removal supplier must report a reversal event.
• Definitions: clarified Removal, added Monitoring Plan. 

4.0 Changelog

• Certification with external methodologies process.
• Aligning with ISO/CCP terminology for design validation and performance verification.
• Additional procedures to avoid double counting.
• Aligning trading of CORCS with Article 6 of the Paris Agreement and CORSIA requirements.
• Amending Registry requirements to include carbon removal year of production (vintage).
• Clarifying use of the Platform Agreement.
• Enhance additionality and leakage requirements.
• Rules for reversal events and uncertainty assessment.
• Requirements social safeguards: human rights, Indigenous People, labor rights, gender.
• Requirements for positive Sustainable Development Goals (SDGs) impacts description.
• Ongoing Issuance and Digital Monitoring, Reporting, and Verification.

3.1 Changelog

• Removed Chapter 3.4 Certificate Expiry as per resolution in Advisory Board on 31 May, 2023. CORCs no longer expire automatically after 5 years.
• Chapter numbering from Ch 3.5 unchanged for reference.

3.0 Changelog

• CORC minimum durability set to 100 years
• Annex C discontinued: CORC issuance on Bio-based Building
• Materials methodology (storage durability of 50 years) ceased from January 2023.
• Chapter 1.2.3 added: reference to normative documents
• Chapter 2.1.4 added: reference to leakage
• Chapter 4 revised: description of “transfer of ownership” of a CORC instructed with a trade report
• Chapter 5 revised to allow publishing of Audit Reports and project description
• Enhanced Rock Weathering added as a valid Methodology.
• All Methodologies and templates published as separate documents in Puro.earth website. Annex A-H removed from this document

2.7 Changelog

• Annex B: Carbonated Building Material update from 2019 to 2022 to reflect the latest science
• Chapter 1.3: Governance rules updated

2.6.1 Changelog

• Page numbers corrected in Table of Contents

2.6 Changelog

• Annex H: Woody Biomass Burial

2.5.1 Changelog

• Minor spelling mistakes corrected

2.5 Changelog

• Renaming of “Direct Purchase” to “Service Provider Trade” to align to Appendix 1 Terms and Conditions. 
• 4.2 Clarification of conditions related to Service Provider Trade.

2.4.1 Changelog

• Annex A: Biochar chapter 4.2 – Spelling correction of 𝐶𝑜𝑟𝑔  

2.4 Changelog

• Terminology change: replace “cancel/retirement” with “retire/retirement” 
• 5.1 Reporting: Added possibility for beneficiary to delay (embargo) the publishing of the retirement for maximum 12 months 

2.3 Changelog

• 2.1.2 Environmental and social safeguards 
• 2.1.3 Additionality and Baseline 
• Annex A: Biochar methodology update from 2019 to 2022 to reflect the latest science 

2.2 Changelog

• Chapter 1.3: Governance by Advisory Board
• Chapter 3.8: Expiry extended
• Chapter 5: Issuance and cancellation reports from the Registry

2.1 Changelog

• Re-structuring: Separate chapters to describe rules for trading (Marketplace) and carbon removal crediting (Registry and Standard)
• Annex G: Geologically stored Carbon methodology

2.0 Changelog

• Chapter 3.1: Settlement is no longer tied to auctions
• Chapter 3.4: Purchase through Certificate Listing Service enabled
• Chapter 3.4: Pre-Purchase transactions enabled outside auctions
• Chapter 3.4.3: Transfer Request added to Pre-purchase agreement process 
• Chapter 4.3: Sale of CORCs enabled in external marketplaces
• Annex A, 1.1.12: requirements for safe handling of biochar

1.4 Changelog

• Chapter 3.7 and 6.2: Extension of the expiry date by 6 months 
• Chapter 3.5.6: Online shop closed for 3 hours before and after the auction 
• Chapter 3.5: Possibility to select removal method in online shop 
• Numbering of subparagraphs in Chapter 1.5. and Annex A,B,C 

1.3 Changelog

• Chapter 3.3: Certificate auctioning (changes from 48h blind to 96h half-blind)
• Chapter 3.4: Pre-purchase of Certificates (changes due to action mechanism update)
• Chapter 3.5 Certificate online purchase (added)
• Chapter 6.2: CORCs issued in Experiment phase will expire normally 12 months after Issuance date. 

1.2 Changelog

• Chapter 3.2.4: CORCs may be issued for 18 months old production (previously 12 months)
• Chapter 3.3: editorial changes 
• Chapter 3.4: Pre-purchase of Certificates (CORCs)
• Chapter 6.4: Aim to use CORC income for growth

1.1 Changelog

• Annex C. Wooden Building element methodology modified to incorporate also biomass-based insulation materials. 
• Annex F. List of signatories included confidentially (not changed)

1.0 Changelog

• Initial version elaborated with List of Signatories and published on puro.earth website on the launch date of Puro CO2 removal marketplace.