Pre-emptive acknowledgement of something that may or may not have been agreed.
1> Used in an attempt to pre-empt further discussion by assuming agreement.
2> Used to reinforce agreement when it is mutually assumed.
3> Used as a greeting to imply the discussion or meeting occurance was previously agreed upon.
1> "Meet at Westbahnhof as agreed" - When you are at Westbahnhof and want your friends to come without discussion.
2> "So should I come around to your house as agreed?"
"Yeah man, as agreed!"
3> "As agreed bro, how have you been?"