magic variables

Is there a comprehensive list of all the magic varialbes?

I've been using $inventory_hostname a lot. Right I'm looking for the user name of the user running the playbook, etc... Every time I am about to register a variable from a command, I'm wondering if what I'm looking for isn't in a magic variable already.

https://groups.google.com/forum/?fromgroups=#!searchin/ansible-project/template_/ansible-project/paudzD0SnlM/wWLfH49XoDQJ

Docs should be in better order shortly, if not already, as
$inventory_hostname is not really just a *template* variable and there
is hostvars and such.

I'll make a note to make a better docs section.