Significant changes to the organization and its supply chain 2020 Annual Report 102-11 Precautionary Principle or approach Comerica’s 2020 10-K (Item 1A-Risk Factors) 102-12 External initiatives In 2020, Comerica signed the Partnership for Carbon Accounting Financials (PCAF) commitment to support the development of and to begin to report on our finance-related greenhouse gas emissions within three years.