5. An assessor keeps up to date, for the purposes of analysis and comparison in the assessment process, a record of neighbourhood units in which each unit is described using the information in Part 2D of the Manual.
A neighbourhood unit comprises units of assessment that are close to each other, have similar characteristics and are located in a similar environment.
M.O. 94-09-01, s. 5; M.O. 2010-07-20, s. 2.