上述 (shàng shù) is a formal adjective meaning 'aforementioned, above-mentioned' — it directly modifies a noun (e.g., 上述报告). It is more precise and written than 上面 (shàng miàn, which can also mean 'above-mentioned' but is a noun and less formal), and differs from 以上 (yǐ shàng, a noun often used to conclude a list or refer to 'the above' as a whole). Use 上述 when you need a concise, formal reference to something already stated in the same text.