Comment 0 for bug 1189280

https://help.ubuntu.com/13.04/ubuntu-help/tips-specialchars.html

Ctrl+F to "Define a compose key"
See step 4.

The phrase
"...Any keys you select will then only work as a compose key, and will no longer work for their original purpose."
could be
"...Then, any keys you select will only work as a compose key and no longer perform its original purpose."