I have begun the arduous task of converting a large data set (60 km+ of passage) from Survex to Therion in line with the rest of the data that we keep. Much of this is quite old, 1950s and 1960s. In many cases we do not have clino data and, in Survex, I have either ignored this fact or have manipulated the data by inserting fixes including altitudes at known points, usually entrances. This would skew the model to give a reasonable approximation of its 3d shape. I discover that Therion will not simply ignore the lack of clino readings but tells me that there is "not all data for given style" if I have put in this line "data normal from to length bearing ignoreall" This concerns me on two fronts: firstly does it mean that I have to go back in and type an arbitrary list of zeros at the end of each data line? Secondly, when it processes the cave does this mean that the process will give due meaning to all those zeros and adjust the model differently to how it would do so if they were not there (as in Survex)? Graham