Supposedly this variant is popular in Hong Kong's Victoria Park.
All the pieces, except the kings, are turned over so you can't see what they are. You mix them up so you don't know what they are, and place them all on the starting points. Then you turn over a piece as you move it. I don't have many more details than this. This is another advantage of using flat pieces--you can turn them over & play variants such as this one.
Text mainly from Stephen Leary's FAQ for rec.games.chinese.chess.
Last modified: February 27, 1997.