At the centre of this Action are six Working Groups, the scope of which is determined by the basic features of letters themselves. Letters are written documents sent by a one or more person(s) at a specific time and place to one or more other person(s) in another place. The spatial and temporal, personal, textual, and material features of letters structure the agenda of four Working Groups; while the other two Working Groups are devoted to the means of bringing data on all these dimensions together and rendering it visible and intelligible to a variety of audiences. The briefing document detailing the functioning of the Working Groups is available for download here.