Rauch classifies goods (using industy codes) in three categories, according to whether each industry is: a) sold on an exchange; b) reference priced; c) or neither. Is there any similar classification for services as well?
My Italian is too poor to understand Alessio Ciarlone's answer. Would English be possible?
Apart from that: I know that the international trade center (intracen.org) is working on identifying services in international trade. They may have created a database with corresponding coding; haven't checked it, though.