Not really missed, but I’m writing this from Taiwan because my original flight to the Philippines was cancelled due to bad weather. So we started looking at weather forecasts at the airport and jumped on the next flight to the country with the best weather!
Yep, this is the answer. In Fortran, all variables are assumed to be floats, unless the variable starts with I, J, K, L, M or N. I’m sure they had a good reason, but it sounds so bizarre today!