Personal boxes emptied by Royal Mail would not have to hold a cypher. Royal Mail article boxes manufactured considering that 1994 have the wording 'Royal Mail', normally over the aperture (lamp boxes) or about the door (pillar boxes). In advance of this date all publish boxes, excluding the Nameless pillar https://contemporaryletterbox33086.alltdesign.com/not-known-facts-about-letterboxes-melbourne-47999511