1. An event-handling system that receives from one or more sources one or more events, each event having data associated therewith by the issuing source, the associated data including a semantic and an ordered data value, wherein said event-handling system makes available one or more events to one or more recipient systems, said event-handling system comprising; one or more event lists having a predetermined semantic; and a means to determine events to be made available to said one or more recipient systems if an event has an ordered data value within one or more defined data value ranges.