A rareearth element (REE) or rareearth metal (REM), as defined by IUPAC, is one of a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides, as well as scandium and yttrium.
The MACRS Asset Life table is derived from Revenue Procedure 8756 19872 CB 674. The table specifies asset lives for property subject to depreciation under the general depreciation system provided in section 168(a) of the IRC or the alternative depreciation system provided in section 168(g).