on a collection plate fixed to the box. In urban areas, this might be once or twice a day. Busy boxes might be cleared more frequently to avoid overflowing, and also to spread the work for the sorters. Extra clearances are made in the period leading up to Christmas, to prevent boxes becoming clogged with mail. Since 2005, most Royal Mail post boxes have had the time of only the last collection of the day shown on the box, with no indication of whether the box is cleared at other times earlier in the day. Royal Mail say they needed to increase the type size of the wording on the plate to help those with poor sight, and so there was not enough room to list all collection times throughout the day. Some post boxes may indicate the next collection time by a metal 'tab' or dial that can be changed while the box is open. The tab displays a day or number, each number corresponding to a different time shown on the plate. Some boxes have been used as a dumping ground for used hypodermic needles. In such cases staff are issued with protective equipment. Terrorism and political vandalism United Kingdom Scotland In 1952, a number of post boxes were attacked in Scotland in a dispute over the regnal number adopted by Queen Elizabeth II, which was displayed as the EIIR cypher. This included at least one damaged in Gilmerton Road, The Inch, Edinburgh by a homemade explosive device. This was because many Scottish people did not believe Queen Elizabeth II should take that title. Rather Elizabeth Queen of Scots as Scotland had never had a Queen Elizabeth before. Following a civil case in the Scottish courts, a compromise was reached where the Crown of Scotland was placed upon Scottish pillar boxes in place of the St Edward's Crown, without any reference to the particular reigning monarch. To this day Scottish post boxes and Royal Mail vans use the Scottish Crown with no mention of Queen Elizabeth II. The Troubles During 1939 a number of bombs were put in post boxes by the IRA as part of their S-Plan campaign. When the Provisional IRA blew up the Arndale shopping centre in the 1996 Manchester bombing, one of the few things to survive unscathed was a Victorian pillar box dating from 1887 (a type A Jubilee pillar). In Northern Ireland