A more thorough explanation:

Definition: Warrantia custodiae is a legal term in Latin that refers to a writ used by a purchaser of land held in knight's service against the seller (and heirs). The seller had warranted that the land was free of wardship when a wardship was later claimed.

Example: Let's say that John sells a piece of land to Jane and warrants that the land is free of wardship. Later, it is discovered that the land is actually subject to wardship. In this case, Jane can use a warrantia custodiae to hold John (and his heirs) responsible for the wardship.

Explanation: The example illustrates how warrantia custodiae works in practice. It shows that if a seller makes a false claim about the land being free of wardship, the purchaser can use this writ to seek compensation from the seller (and their heirs) for any damages or losses incurred as a result of the wardship.