There is a difference in Japanese and Chinese in printing typefaces for this third stroke of this radical. In the Kangxi Dictionary and in Japanese,a vertical line slanting upwards to the right is used on top of the first horizontal line. In China, Taiwan, and Hong Kong, a slanted dash slanting downwards to the right, or Radical 3, on top of the horizontal line is used.
Fazzioli, Edoardo (1987). Chinese calligraphy : from pictograph to ideogram : the history of 214 essential Chinese/Japanese characters. calligraphy by Rebecca Hon Ko. New York: Abbeville Press. ISBN0-89659-774-1.