1. Web Authentication API

    The Web Authentication API is an extension of the Credential Management API that enables strong authentication with public key cryptography, enabling password-less authentication and / or secure second-factor authentication without SMS texts.

  2. navigator api: registerprotocolhandler: `scheme` parameter supports `sms`

  3. navigator api: registerprotocolhandler: `scheme` parameter supports `smsto`

  4. html element: a: href: `href = 'sms:'`