Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/ Upstream-Name: tthsum Source: http://tthsum.devs.nu/ Files: * Copyright: 2004-2013 Walter Doekes License: GPL-3+ Files: debian/* Copyright: 2005 RISKO Gergely 2012-2014 Hector Oron License: GPL-3+ License: GPL-3+ tthsum is copyright under the GNU General Public License (version 2 or higher). the hashing code has been copied from GPL'ed DC++ with as few modifications as possible. . You can find the mentioned GNU General Public License (GPL) (on a Debian system) in the file /usr/share/common-licenses/GPL-2.