You can change the spatial reference system (SRS) to any common EPSG defined system. For each common system a EPSG-code exist. More than 3500 of them are integrated into MAVinci Desktop. You can select the SRS for the map manager (also the default for new sessions as well). Inside the settings panel, or by double clicking onto the ``EPSG:.....'' text in the lower left corner of the map layer manager window. For changing the SRS inside a session, you could double click into its lower left map corner as well, or by the menu ``Post processing'' → ``Choose SRS...''. In all cases the dialog show in in Figure 70 will show up. You could search for a system by typing a number or name in the upper text field. You could define your own SRS systems based on a WKT definition (see http://en.wikipedia.org/wiki/Well-known_text). Please be careful deleting private SRS, as they might be still in used in some of your old sessions.