This rule establishes the procedures for an Incorporated Body to carry forward tax losses. A loss can be deducted from the net income of subsequent years for a maximum of three years. The right to carry forward losses is forfeited upon events such as ceasing activity, liquidation, merger, or a change in the legal form of the body. The rule distinguishes between different types of activity cessation, noting that force majeure events also prevent loss carry-forward. It provides guidance on pre-existing losses under older decrees and includes illustrative examples.