Wave: send a message to the receiver that only contains the senders identity - no content - the meaning is context dependent, may be influenced by ui(the change from poke to wave), or subverted by users.
Mapping: UI element where a user provide asynchronous signal to a recipient of their attention. Is sent and received .
Examples: Wave on Facebook (replaced ‘poke’)
Also know as: like(person), poke(archaic fb)
Related concepts: Upvote(media)
(please feel free to edit/correct)