For the numbers, I opened the first 10 maps I had, alphabetically, and 3 of them had values for title and author (noteworthy that the titles often differed from the filename of the map). Not sure if such a low number using these fields would be worthwhile for making any type of data base. I think if the engine actually made use of the data, such as
displaying it with a map preview. Like the description element in the techtree XML, these fields were created by the original Glest Team, but never used in game. Some modders use them for no particular reason, but others won't because, well, they don't do anything. What good is typing your name as the author of the map if nobody will see it?