This document discusses extrapolation in consumption registers. It defines key terminology used in extrapolation like weighting procedures, weighting keys, and weighting units. It explains how the system determines if a period is representative for extrapolation based on minimum portion percentage and period length. If a period is not representative, extrapolation is based on periodic consumption rather than meter readings. The document provides an example of forecasting from previous periods with minimum portions, and demonstrates how estimated meter readings are calculated and can change based on actual readings or consumption changes.