1. A computer system for enabling collaborative document markup between participants, the computer system being adapted to receive indicating data from a sensing device operated by a participant involved a collaborative document markup session in conjunction with at least one document markup form containing information relating to the document markup session and including coded data indicative of an identity of the document markup form and of at least one reference point of the document markup form; said indicating data regarding the identity of the document markup form and a position of the sensing device relative to the document markup form, the sensing device, when placed in an operative position relative to the document markup form, sensing the indicating data using at least some of the coded data, said computer system including means for identifying, from the indicating data, at least one parameter relating to the document markup session; the computer system further being adapted to provide at least one other participant remote from said participant with at least one document markup form containing information representative of the at least one parameter. means for providing at least one other participant remote from said participant with at least one document markup form containing information representative of the at least one parameter.