A Dictionary of Slang, Cant, and Vulgar Words by John Camden Hotten

“Gipseys follow their brethren by numerous marks, such as strewing handfuls of grass in the day time at a four lane or cross roads; the grass being strewn down the road the gang have taken; also, by a cross being made on the ground with a stick or knife, the longest end of the cross denotes the route taken. In the night time a cleft stick is placed in the fence at the cross roads, with an arm pointing down the road their comrades have taken. The marks are always placed on the left-hand side, so that the stragglers can easily and readily find them.”—Snowden’s Magistrate’s Assistant, 1852, p. 444.