xWSS

xWSS (also XWSS or *WSS) is a term used to designate any of the standard c/2 orthgonal spaceships in Conway's Game of Life:

• the lightweight spaceship (LWSS)
• the middleweight spaceship (MWSS)
• the heavyweight spaceship (HWSS)

The glider, overweight spaceships, flotillae and non-standard spaceships are not subsumed under the term xWSS; neither are spaceships not found in Conway Life.