I've added "alt_name = Eastgate" to the stretch of Rochester High Street between Star Hill and the old city wall. I'm not sure what the status of this name is. It appears on all OS maps since the 19th century. It's still there on OS Locator (which is what drew my attention to it). However, the numbering of the street simply continues the numbering of the High Street within the city walls. The Royal Mail's address file doesn't recognize it - properties in Eastgate have High Street addresses. Yet I'm pretty sure there used to be a street-name sign at the Star Hill end when I was a lad (we used to wait for buses outside the Seeboard show-room). The Medway Map Service (http://medgis.medway.gov.uk/) doesn't recognize Eastgate as a street-name either - which presumably means it's not in the official List of Streets. (If you click on the street in Identify Feature mode, it names it as High Street.) Maybe it should be old_name rather than alt_name, but somehow the fact that the OS still uses it persuaded me to go for alt_name. Google throws up some references to numbered addresses in Eastgate - e.g. "W. Naylar and Son, 191 eastgate, Rochester, funeral directors". These are generally in historical documents, though.