mkay, well without trying it myself, i'd suggest writing a small script - in fact here:
;get the names of weapons
hint format["%1 \n %2","tank1", weapons tank1]
~10
hint format["%1 \n %2","tank2", weapons tank2]
~10
hint format["%1 \n %2","tank3", weapons tank3]
~10
exit
copy paste that into notepad, save as "what_weapons.sqs", then in your mission, put
[] exec "what_weapons.sqs"
in the init line of anything. this should work, assuming you've named your vehicles tank1, tank2 etc.
also note - there is a list of all the things you want in the official BIS comref. get it from
this page.