I only recently found out about this one, it's for "convenient tags". Basically, you can write any word instead of numbers to link a channel, for example DOOR1 or something instead, and the maptags file will link these with tag numbers. I got rid of it fast myself, as it's not something I'd need myself - the file is created even if you mistakenly write a letter instead of a number while putting the tag. Don't think it's necessary to include in the release, I think the name-tags are only used for the editing maps, but then it gets converted to numbers, as I've never seen one attached with a map - but I'd recommend doing a quick check if the map alone would work without it, or even better checking that on a short example map with one activator-open door using a convenient door tag instead of regular one.