1. A method of generating a variable-data printing document template in a computer readable format, the template defining multiple document versions, with each document version being selectable in response to input selection data, the method comprising: defining a template comprising a layout of document portions, at least one set of the document portions comprising a flow that contains content which is variable in response to input data, the flow spanning across the set of document portions; and defining a plurality of document versions, different document versions comprising different combinations of document portions of the set, and indicating the desired variable content of the flow, wherein the continuity of the flow is maintained when a version is selected in response to input selection data.