I would like to discuss the standardization of a mechanism with which user agents can choose (through the User Interface), to trust or to not trust a specific version of a web page or a set of web resources forming a webapp. Example use cases for this would be Tutanota email service, or Protonmail email service. The users of these services could trust a version of the served webapp so that they can know these are not being modified on-the-fly potentially with added backdoors. An update for that webapp would have to be approved again by the user.