Why two (identical) tarballs for a release?

[boegel]

I was wondering why an additional tarball is uploaded for each release, while the tarball that is already available is basically identical (other than the name of the Makefile, which is kind of strange):

$ diff -ru cdhit-4.6.6 cd-hit-v4.6.6-2016-0711
Only in cd-hit-v4.6.6-2016-0711: makefile
Only in cdhit-4.6.6: Makefile
$ diff -u cdhit-4.6.6/Makefile cd-hit-v4.6.6-2016-0711/makefile
$ 

Is there a particular reason to provide both cdhit-4.6.6.tar.gz and cd-hit-v4.6.6-2016-0711.tar.gz?

Is cdhit-4.6.6.tar.gz safe to use as well? It's easier to use in a scripted manner since you can easily guess the tarball name based on the version.

cc @SethosII