AuthenticatorAssertionResponse.authenticatorData - Web APIs
bit 6, attested credential data (at) - if set, attestedcredentialdata will immediately follow the first 37 bytes of this authenticatordata.
...extension data will follow attestedcredentialdata if it is present, or will immediatelly follow the first 37 bytes of the authenticatordata if no attestedcredentialdata is present.
... attestedcredentialdata (variable length) - the credential that was created.

CredentialsContainer.create() - Web APIs
the options are: password: optional either an htmlformelement, or a passwordcredentialdata object.
... tbd id: (required) usvstring inherited from credentialdata.
...the available options are: id: (required) usvstring inherited from credentialdata.

Attestation and Assertion - Web APIs
the authenticator data contains an attestedcredentialdata field.
... the attestedcredentialdata field contains the credentialid and credentialpublickey.
...the attestedcredentialdata is an optional field used in attestation.

AuthenticatorAttestationResponse.attestationObject - Web APIs
when used in attestation, it contains an optional field, attestedcredentialdata.
...the attestedcredentialdata field contains the credentialid and credentialpublickey.

PasswordCredential - Web APIs
syntax var mycredential = new passwordcredential(passwordcredentialdata) var mycredential = new passwordcredential(htmlformelement) parameters either of the following: passwordcredentialdata a passwordcredentialdata dictionary containing the following fields: iconurl: (optional) the url of a user's avatar image.