This specification describes the XFS service class of check readers and scanners. Check image scanners are treated as a special case of check readers, i.e. image-enabled instances of the latter. This class includes devices with a range of features, from small hand-held read-only devices to much larger devices (i.e., tabletop). The high end device of this class usually found in bank branches shares many capabilities with the still larger devices usually found only in a bank's central data processing site (i.e., high-speed reader/sorters), but the latter are not explicitly addressed here. The specification of this service class includes definitions of the service-specific commands that can be issued, using the WFSAsyncExecute, WFSExecute, WFSGetInfo and WFSAsyncGetInfo functions.