I wrote an ovl.c and have additional entrys to vecs.c to read and write
ovl Files for Geogrid Viewer by Dornier that is delivered with TOP Maps by=
authorities eg TOP 25 BW or TOP 50.
There is an entry in the CVS System for that.
At the moment it is not possible to convert anything but coords tupples.
I plan to add also description by putting text and circle to a coordinate,
if the simple version works. If that works I will see how to handle tracks=
I used a modified ovl.c the write a sample.ovl that could be read by my
geogrid viewer and imported a ovl written by my geogrid viewer.