A khoji is a tracker: a person who can read footprints in sand and dust and follow a man, an animal or a cart across country.
It was a recognised profession in Punjab and Sindh, used to trace stolen cattle, which in the bar country was the standard crime, and to follow thieves. The khoji's evidence was accepted in village dispute settlement and in some cases by courts.
The skill is specific and learned: reading depth, gait, load, age of the track, and distinguishing individuals.
The Border Security Force employs trackers on the Punjab and Rajasthan borders for exactly this, and the skill survives there because a smuggler crossing a ploughed strip leaves marks.
It is one of the oldest specialised occupations in this landscape and it survives now almost entirely inside a security force.
Nobody has recorded how it is taught.
A khoji reads the ground for direction, for how many, for how heavy and for how long ago. The judgement about time is made from the edges of the print and from how the sand has moved in it.
The Punjab and Sindh police used khojis formally into the twentieth century and a khoji attached to a police station was a post with a name and a pay scale. Cattle theft in the bar districts kept the profession employed for as long as cattle were the wealth worth stealing.
The Border Security Force trains and employs trackers and recruits from families that already have the skill. There is no manual and no course outside that.