Source: http://www.flickr.com.Uploaded to Flickr by Karen Horton and tagged with "churchwarddesign". License: CC BY-NC.

c. 1973, Europa CEPT issue

The design that year, a stylised post horn, was made by the Norwegian artist Leif Frimann Anisdahl (24 countries; 50 stamps). The 3 arrows are said to represent CEPT's primary objectives: post, telegraph and telephone services — Europa-Stamps blog