A more thorough explanation:

The agreed-boundary doctrine is a principle used by adjacent landowners to resolve uncertainties over land boundaries by permanently fixing the boundaries through an agreement. This means that owners of contiguous land can agree on the boundary between their parcels, as long as certain conditions are met.

The conditions for the agreed-boundary doctrine to apply are:

• The actual boundary is uncertain
• There is agreement between the two owners about the boundary line
• There is acquiescence in the agreed line for a time exceeding the statute of limitations
• The agreed boundary is identifiable on the ground

For example, if two neighbors have been using a certain fence as the boundary line between their properties for over 20 years, and both agree that the fence is the boundary line, then the agreed-boundary doctrine can be applied. As long as the fence is identifiable on the ground and there is no dispute between the neighbors, the boundary line can be permanently fixed through an agreement.

Another example could be if two neighbors have been using a certain tree as the boundary marker between their properties for over 10 years, and both agree that the tree is the boundary marker. As long as the tree is identifiable on the ground and there is no dispute between the neighbors, the agreed-boundary doctrine can be applied to permanently fix the boundary line.