A boundary line agreement, although not allowed in all towns, is when the boundary lines of two properties are agreed to and witnessed by a deed. Although restricted in some areas of the state, if the conditions can be met a boundary line agreement is an excellent tool for resolving small discrepancies between properties. A survey map and multiple suggested legal descriptions may be required for your attorney's use in preparing the deed of conveyance. Having the right attorney is very important. Local zoning codes have to be observed and subdivision approval is not necessarily required.
Samples of my boundary line agreement work can be found here: legendlandsurveying.com/page33.php