Google wave – nice error message on contact search

Wave rules, but I can’t find the meaning of the message:  could not be found. Would you like to add it to your contacts?
If the contact is not found, how can it be added. Unless the meaning is: Search for a contact in “mine contacts list”. It is not found in “mine contacts list”, but there exists a account in the “global account list”, would you like to add the contact to “you’re contact list”?