Software that LIGO is not legally allowed to redistribute (such as the Dolphin IX drivers) are available in a restricted archive. The best way to enable this archive is to create a separate sources list for restricted archive:
Software that LIGO is not legally allowed to redistribute (such as the Dolphin IX drivers) are available in a restricted archive. The best way to enable this archive is to first install the cdssoft-release-* package as described above, and then create a separate sources list for restricted archive:
```shell
# /etc/apt/sources.list.d/cdssoft-restricted.list
deb [signed-by=/usr/share/keyrings/cdssoft-unstable-archive-keyring.gpg] https://$USER:$PASSWORD@apt.ligo-wa.caltech.edu/debian stretch-restricted main