In the Hotkey's section of the manual, it says:
Ctrl-u Starts a prefix entry sequence
What does this mean? I can't find any other reference to it.
Ignore it. It needs to be removed from the manual. This is a left over remnant of years ago, when Ardour took keybinding inspiration from the audio editor "snd", and thus from the text editor "emacs". Its been gone for quite a long time.
Your subscriptions & donations are critical help that make it possible for full-time development of Ardour to continue. Your support is critical and much appreciated.
July goal US$4500 (US$54k/yr)
Total till now: US$884.78
Subscribers 900 US$1806/month
Support Ardour, get free upgrades: pay $1, $4, $10 or $50/month for a year: