Every nation has dictionaries and grammar for harmonising and developing their literary standards. For almost a century, Estonians have had dictionaries of standard language as their main dictionaries. The first dictionary of this kind was the Estonian spelling dictionary, published as a publication of the Estonian Literary Society in Tallinn in 1918. This dictionary harmonised the Estonian Literary Standard and laid the foundation for the practice of the dictionaries of standard language.
Over the century, over ten dictionaries have been published in Estonia with the word “standard language” or abbreviation “ÕS” in their title: 1918, 1925–1937, 1933, 1938 (school dictionary), 1948–1951 (remained in progress), 1953, 1960, 1976, 1999, 2004 (student ÕS), 2006, 2013. This year, the 13th ÕS, i.e. the 2018 Dictionary of Standard Estonia, will be published.
About this stamps in philately foorum.