There must have been millions of these cards in circulation in the early 1920s. This particular run was printed in September 1921 and the document is commonly seen in soldiers' service records of the First World War. It accompanied the campaign medals sent to soldiers and was supposed to be completed, signed and returned by the recipient. This card was, which is how it surives in this soldier's file, but many of these examples, along with the medal boxes, are also commonly seen with medal groups and a nice addition when they do survive.
These images are Crown Copyright, The National Archives.