p.boxed
  | Pawns can capture backward.

p.
  Orthodox chess, with enhanced pawns: they can capture forward as usual,
  and also bacwkard - always by one diagonal step.

figure.diagram-container
  .diagram
    | fen:k7/2B5/3p4/2p1p3/2P1P3/3P1n2/8/K7:
  figcaption The bishop and the knight are under attack.

h3 Source

p
  | This seems to be an original idea of José Victor Gonçalves, thus the name
  | "Victor-Chess", abridged into Vchess.
  | Some other variants with different pawn movements are listed 
  a(href="https://www.chessvariants.com/other.dir/modest-pawn.html")
    | on this page
  | .