one of the documented procedures in this installation of the ACS
export_entire_form_as_url_vars   { vars_to_passthrough "" }
What it does:
Returns a URL parameter string of name-value pairs of all the form parameters passed to this page. If vars_to_passthrough is given, it should be a list of parameter names that will be the only ones passed through.
Defined in: /web/philip/packages/acs-core/utilities-procs.tcl

Source code:

    set params [list]
    set the_form [ns_getform]
    for {set i 0} {$i<[ns_set size $the_form]} {incr i} {
	set varname [ns_set key $the_form $i]
	set varvalue [ns_set value $the_form $i]
	if { $vars_to_passthrough == "" || ([lsearch -exact $vars_to_passthrough $varname] != -1) } {
	    lappend params "$varname=[ns_urlencode $varvalue]" 
    return [join $params "&"]