On this date in 1922 the British Broadcasting Corporation was formed by a group of six telecommunications companies. The BBC was the world's first national broadcasting organization and made their first transmission in November 1922 from station 2LO in London.
This series of small triangular stickers were used to help listeners mark the dial locations of various BBC stations in their local market. Click the sticker for a close-up view.
Here's a set specifically for BBC Radio 4.