Access Control Lists control permitted actions on protected network computer system resources by providing an access control policy associated with the requested protected system resource containing a permission list of permitted identities and at least one action group tag with associated action indicators; reusing a finite quantity of action indicators among a plurality of action group tags to control a number of unique permissions less than or equal to the product of the quantity of allowable action indicators and a quantity of allowable action group tags; evaluating the permission list according to a specific permission definition associated with the action group tag, the permission definition providing a correlation between members of a set of action indicators; and granting authorization to perform actions on the requested protected system resource to the requesting user if the access control policy permission list includes an appropriate action indicator correlated to an action group tag.