What is the term for an implied boundary agreement based on accepted features like fence lines?

The correct term for an implied boundary agreement based on accepted features like fence lines is Boundary by Acquiescence. This concept arises when two property owners agree to an informal boundary that has been recognized and accepted over time, typically through long-standing use, such as a fence that both parties have allowed to remain in its position.

Boundary by Acquiescence occurs when one party acknowledges the other's claim to the land, usually due to their actions and acceptance of a particular boundary rather than a formal survey or recorded document defining the boundary line. This type of agreement is established through the absence of disputes and the recognition that both parties have acted according to the accepted line.

Other terms such as Boundary by Agreement refer to a more formal, explicit agreement that is usually documented, while Boundary by Estoppel involves a party being prevented from denying a boundary that has been established through reliance on another party's representation. Boundary by Prescription requires continuous and open use of the land for a statutory period to claim ownership, which distinguishes it from the informal and implied nature of Boundary by Acquiescence.