Thank you for that. I found your list previously but did not find what I was looking for.For instance, we can use %{recipient.email} that is not in this list.I am sure there are a few other ones. Is your list official or you did it by yourself and post it?If it is an unofficial, I think that it can also be a good investment to list everything that we can use. But how to that? it is certainly somewhere in the code, I will try to have a look on that.