Nothingness:
Above the opponent's side of the board there is a "Captured pieces:" list with the identities if those pieces the opponent has captured, and below one's own side of the board board there is a "Captured pieces:" list with the identities if those pieces you captured and "?" for unidentified captured pieces. Pieces show up on the list whether captured by successful attack or unsuccessful attack. Any time a piece is moved to a square occupied by an enemy piece, one of those pieces will be captured.
There is no capture on a move that the pieces moved all move to unoccupied squares.
Sorry for not properly linking my previous post.