Organizations engaging in electronic commerce typically are faced with high set-up costs for new electronic linkages due to the need for detailed bilateral agreements. This paper contributes to this problem in three ways by: 1) stipulating requirements on representation languages to be used for modeling trade procedures; 2) presenting a common graph-based representation language, Documentary Petri Nets, which satisfies these requirements; and 3) presenting a 'soft-coding' architecture and protocol for sharing and negotiating trade procedures. A modeling environment, Case/Open-edi, is demonstrated using a documentary credit procedure example to illustrate these three aspects. Finally, conclusions and directions for further research are given.