As the title says. And sorry if this was posted anywhere (I couldn’t find it).
Do I have to dig in the sources or are they nicely laid out in some topic/docs? If I need to dig in the sources, where is the best place to find them all? (/config/system/*.yml ?)
Also, I believe most are contextual, e.g. only a subset of placeholders are available for the “User Invited to PM” email … how do I find out which placeholders are available? A pointer to the relevant source?