distrib/sets/lists

Hi,

$ cd distrib/sets/lists
$ ./fmt-list -n */*/mi */*/ad.* */*/md.*

When I run the above command, it complains about a few lines that have 4
fields instead of the usual 2 or 3.  Are these lines correct, or should
the fields 3 and 4 have been merged into a single field?

Is there some written documentation about the file format of these files?

Roland