ISO 14064 - Greenhouse Gas Accounting and Verification (Parts 1-3) 2:6.1: 6.1 General requirements

For each stage of the project cycle, the project proponent shall identify, weigh and use applicable criteria and procedures where they exist, and follow current good practice guidance where they do not. It shall choose established criteria and procedures from a recognised source where available; record and justify any departure from them; justify its choice where there is more than one recognised source; set and justify its own where there is none; and, if it has signed up to a GHG programme, meet that programme's requirements.