A type of digital certificate used to verify the ownership and authenticity of a logo or mark. It allows organizations to prove that they have been using a specific logo or brand mark for a defined period, typically for at least one year, even if the logo is not registered as a trademark. CMCs serve as a form of verification for non-trademarked logos, providing a layer of credibility and ownership without the legal protections of a trademark. It allows to implement BIMI without a VMC.