Is a PoE-only thin client an example?

[ChristopherA]

/cc https://github.com/WebOfTrustInfo/rebooting-the-web-of-trust/blob/562bbbf6f73039bd652338ed0c12b75efcba9e09/topics-and-advance-readings/thin-clients.md
/cc @taoeffect

Is a thin client that stores and gossips only about about a specific type of Proof-of-Existence records a good specific example of what you are talking about? Can you define one kind of thin client that is the most minimal in scope and yet is still useful?