Acquisition proceedings for undervalued immovable property where stated consideration understates fair market value to evade tax. Competent authority may initiate acquisition proceedings where it believes an immovable property transfer understates consideration to evade tax or conceal assets, subject to a statutory value threshold and a requirement to record reasons; proceedings require that fair market value exceed apparent consideration by more than fifteen percent. If the fair market value exceeds the apparent consideration by over twenty-five percent, that disparity is conclusive proof of understatement, and transfers for less than fair market value give rise to a rebuttable presumption of improper understatement.