Genghis,
Thanks for posting. They are new to me too. I don't remember seeing them in the TC AIP or in NZ CAA docs. Very surprising that are not widely publicized to pilots.
I am amused to see that, in a British document, the "Emergency Contained" signal is described as being similar to an Umpire's "Safe" signal. Not much use if you are not a baseball fan! 😀