4.6. Values not transmitted from CGI

The following variables are never copied from CGI:

        mv_todo
        mv_todo.submit.x
        mv_todo.submit.y
        mv_todo.return.x
        mv_todo.return.y
        mv_todo.checkout.x
        mv_todo.checkout.y
        mv_todo.todo.x
        mv_todo.todo.y
        mv_todo.map
        mv_doit
        mv_check
        mv_click
        mv_nextpage
        mv_failpage
        mv_successpage
        mv_more_ip
        mv_credit_card_number
        mv_credit_card_cvv2

You can define more with the FormIgnore catalog.cfg directive.