Dd Form 1920: Fill & Download for Free

The designators were codified in 1920, and they weren't meant to necessarily stand for anything. Thus, for basic representative types of ships, like battleships, destroyers, submarines, cruisers, and frigates, for example, were symbolized by a two-letter code that was just the repeat of the first letter of their type (BB, DD, SS, CC, and FF, respectively). This code could then be modified, either by replacing the second later with a designator (like DE for escort destroyer, CG for guided missile cruiser, or CA for armored cruiser) or adding letters (like FFG, DDG or BBG for guided missile-carrying frigates, destroyers, or battleships). So the designation for aircraft carriers, CV, doesn't stand for "carrier vessel" but rather that it was considered a cruiser that carried aircraft rather than a hull type in it's own right (as mentioned before, CA was already taken so they used "voler", the French word for aviation).

As a Clemson class destroyer, USS Stewart DD-224 was commissioned in 1920, it would seem there would be little for the Japanese to learn.

Yes. Two huge changes that overlapped.1) Great Depression. During the 1920's the GOP doubled down on Gilded Age policies and tried to reverse every reform promoted by the Populist and Progressive Movements. The GOP cut the income tax and replaced it with punitive tariffs designed to protect inefficient domestic industries at the expense of more efficient ones. The GOP also tried to reverse as much government regulation as possible, and ignored alarming behaviors especially by Wall Street. Although much more well meaning, Herbert Hoover tried to uphold GOP orthodoxy during the onset of the Great Depression. Anyone remember the infamous Hawley-Smoot Tariff?2) The New Deal forced the GOP to change its rhetoric. By 1937, the GOP was attacking FDR for his excesses -- especially the budget deficit -- but had come to accept most of the the New Deal. The GOP accepted banking regulation and banking insurance as not only necessary but desirable. The GOP accepted that Social Security, conservation programs, and farm support programs were no-brainers.3) Isolationism. As late as 1952, a significant wing of the GOP wanted to shelter behind fortress America. It strongly opposed any intervention beyond the America's. Unlike Trump's MAGA, this wing was opposed to large peacetime armies.4) By 1952, this became a small minority. Many Republicans took a more interventionist worldview after the Pearl Harbor attack 12/8/1941. More Republicans came to recognize that the US had to stay immersed in Europe during early Cold War 1945-1949. By 1950, Republicans were using "Who lost China" as a campaign issue. During the 1952 Republican convention Harold Stassen swung GOP support behind DD Eisenhower in order to marginalize the isolationist candidate Robert Taft. Until the end of the Cold War, the mainstream GOP treated isolationists as cranks.Thanks for the A2A, Pamela