carmelo@carmelo-HP-250-G3-Notebook-PC:~$ sudo add-apt-repository ppa:THE_PPA
[sudo] password di carmelo: 
Cannot add PPA: 'ppa:~THE_PPA/ubuntu/ppa'.
ERROR: '~THE_PPA' user or team does not exist.
carmelo@carmelo-HP-250-G3-Notebook-PC:~$ sudo add-apt-repository -r ppa:<repository-name>/<subdirectpory>
bash: errore di sintassi vicino al token non atteso "newline"
carmelo@carmelo-HP-250-G3-Notebook-PC:~$ sudo add-apt-repository -r ppa:rhythmbox-plugins/ppa
Cannot add PPA: 'ppa:~rhythmbox-plugins/ubuntu/ppa'.
The user named '~rhythmbox-plugins' does not have any PPA
carmelo@carmelo-HP-250-G3-Notebook-PC:~$