Restoring iTerm2 to default values I installed iTerm2, played a bit with the preferences.  

Now I would go back to the initial configuration, but removing the app and finding and removing any file on the disk apparently related to the app does not help: after reinstalling, the preferences are still the modified ones.
I found the answer in iTerm FAQs :: Where does iTerm2 store its settings?:

defaults delete com.googlecode.iterm2