In official contexts, this is effectively the same as a royal seal.
https://en.wikipedia.org/wiki/Seal_(emblem)
Trey The Explainer on YouTube has a great video about “the rarest signature”, which is more like a deep dive on to what exactly is a signature and autograph (and…why)
In official contexts, this is effectively the same as a royal seal.
https://en.wikipedia.org/wiki/Seal_(emblem)