What a mystery these things are. Whilst looking for something else, I came across this explanation, given by Chief Justice Andrew Kirkpatrick for how they work. See if it makes sense to you:

“The Proprietors of New Jersey are tenants in common of the soil. Their mode of securing the common right is by issuing warrants from time to time to the respective Proprietors, according to their respective and several rights, authorizing them to survey and appropriate in severalty the quantities therein contained. Such warrant does not convey a title to the Proprietor; he had that before. It only authorizes him to sever so much from the common stock, and operates as a release to testify such severance. This is manifestly the case when the Proprietor locates for himself. When, instead of locating for himself, he sells his warrant to another, that other becomes a tenant in common with all the Proprietors pro tanto, and in the same manner he proceeds to convert his common into a several right. It is true that the survey made in pursuance of this warrant must be inspected by the Surveyor-General, approved by the Board, and registered in their books; but all this is for the sake of security, order and regularity only, and is by no means the passing of the title. It proves that the title has passed, but it is not the means of passing it.”