In your admin control panel, in the left hand menu:
AdminCP > Languages & Phrases > Phrase Manager
And then at the bottom of the page there is an "Add New Phrase" button.
When you add a phrase it asks you three things:
Which group to put them in: The answer = Front-End Redirect Messages
What the phrase name is: These are the lines like: secretadmirer_acknowledged
What the phrase text is: These are the lines like: Your admiration for that user has been successfully registered.
You need to insert each phrase.
I need to build an installer