Entrust Limited Bundesdruckerei GmbH UK National Cyber Security Centre AppViewX Inc Merkle Tree Certificates (MTC) I-D.ietf-plants-merkle-tree-certs has been defined for the use case of the WebPKI. In this document we explore when and how MTC in parts or full can be used in different use cases. Some of this use-cases may provide benefit for private PKI usage.