MaxItems and Marker parameters.
If the UserName field is not specified, the user name is determined implicitly based on the Amazon Web Services access key ID used to sign the request. This operation works for access keys under the account. Consequently, you can use this operation to manage account root user credentials even if the account has no associated users.
To ensure the security of your account, the secret access key is accessible only during key and user creation.
External DocumentationTo learn more, visit the AWS documentation.