You have to log in because they don't exist, so it defaults to edit mode.
You can take a look at this page:
http://svn.tcwonline.org/viewvc.cgi/...dx&view=markup
It'll tell you what most of the forwards pass for data. The prototype for it will generally contain what data type each parameter is, since they're casted to cell when actually thrown out (char = string, int = cell [i.e. no tag, single variable], etc.)