Which of the following is NOT considered an example of a secret in Vault?

Public certificates are not considered an example of a secret in Vault because they are meant to be shared openly and do not contain sensitive information. Unlike tokens, API keys, and passwords which are sensitive in nature and need to be protected due to the access they provide or the information they reveal, public certificates serve the purpose of establishing trust and verifying identities in secure communications. They are designed to be distributed and are often utilized in public key infrastructure (PKI) systems, making them inherently different from the other options that fall under the category of secrets requiring confidentiality and protection from unauthorized access.