I think I remember a hack that permitted us to not have text while selecting ground. It would be very useful in my patch to have such a thing because I removed geomancers completely and made some new maps... I don't wish to re-brand all the ground just for esthetic purposes.
You can edit all the terrain information in FFTacText. The Geomancy information is just part of their help file, so you can remove that half and just have the generic terrain descriptions.
It's mostly to avoid the problem of having to redo every tile in the map editor, since I don't even need them and it would take a ton of time.
Leaving a blank does not work either.