On Debian systems the full text of the CC0-1.0 license can be found in
/usr/share/common-licenses/CC0-1.0 

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

On Debian systems, the complete text of the GNU General
Public License can be found in `/usr/share/common-licenses/GPL-3'. 

The complete text of the Mozilla Public License 2.0 can be found in
the file `/usr/share/common-licenses/MPL-2.0'.