Due to stupidity on my part, and the seemingly long-lost desire to make software distributions smaller, because bandwidth was a precious commodity of yesteryear, I made a mistake. The mistake is thus: the 1.4d release of xtank had only the source code, and not the documentation packaged in the tar file. Get the documentation from the 1.3f release to make a complete distribution.
The XTank revival project is up and running. You will find any more modern and up to date versions of xtank there.lidl at pix dot net