A roster of world cities was outlined in the GaWC Research Bulletin 5 and ranked cities based on their connectivity through four "advanced producer services": accountancy, advertising, banking/finance, and law.[5] The GaWC inventory identifies three levels of global cities and several sub-ranks. This roster generally denotes cities in which there are offices of certain multinational corporations providing financial and consulting services rather than denoting other cultural, political, and economic centres.
The 2004 rankings acknowledged several new indicators while continuing to rank city economics more heavily than political or cultural factors. The 2008 roster, similar to the 1998 version, is sorted into categories of "Alpha" world cities (with four sub-categories), "Beta" world cities (three sub-categories), "Gamma" world cities (three sub-categories), and additional cities with "High sufficiency" or "Sufficiency" world city presence.