dunpconsolefunctions() I think will list them
Otherwise in console you can type 'clientcmd' and press tab to cycle through them
As far as arguments, you can look at add-ons that use it ( I personally keep a copy of alpha bl + rtb for reference, though any game with uncompiled scripts would do) or just use the search function and search in coding help+mod discussion
Otherwise you can brown townyze each argument
Three numbers is a vector: a position (usually) or direction
A number in the hundreds/low thousands is probably a datablock
Anything else you can .getDatablock().getName() or .getClassname()
