This seems like a re-invention of the Maidenhead Locator System: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Maidenhead_Locator_System" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Maidenhead_Locator_System</a>