Certified and Custom Connector - Security & Compliance

[eSmiddy]

Are certified connectors required to go through any ATO and/or security compliance check? Can publishers elect to get their certified connectors ATO'ed, and if so, how would users of those connectors know a particular connector is ATO'ed?

Or do all certified connectors adopt Power Platform's security and accreditation status? And does that also apply to custom connectors?

Thank you in advance!