This clarifies the valuation method for real estate developers applying transitional rules under Ministerial Decision No. 120 of 2023, which allows them to elect to exclude gains on Qualifying Immovable Property" attributable to the pre-Corporate Tax ownership period. The definition of "disposal" aligns with accounting revenue recognition standards, such as IFRS 15's percentage of completion method. The excludable gain is calculated based on the difference between the property's Market Value at the start of the first tax period and the higher of its original cost or its net book value at that same date."