This Rule outlines the provisions for deducting reimbursable costs from total revenues before calculating net profit under a deemed accounting basis. It stipulates that such costs must be necessary for contract execution, clearly stated, and substantiated by proper documentation. A key condition is that these costs must not exceed 30% of annual revenue. Should this threshold be surpassed, the company is required to file its tax declaration based on regular accounts, subject to actual documentary inspection. The Rule also clarifies the calculation methodology for other expenses.