I am still dealing with a lot of legacy data from the 1950s and 1960s where clinos were not used. Using Survex this is not a problem, as I just enter the data after a line: data normal from to compass tape ignoreall and the program will run. In Therion, however, the same circumstance gives the error message: -- not all data for given style This is a problem as it would require me to enter a series of zeros, which does not equate to reality. In some caves, the altitudes are constrained by the use of fixed points, at multiple entrances, which allows for this data lack. In Therion I am not so sure how this will work. Graham