In 1950, the American Paddle Tennis Association was renamed the American Platform Tennis Association (see Annual Meeting Minutes).
As explained by Fess Blanchard, this was a positive move because, “despite the fact that our game developed into something very different from the original paddle tennis, we gave it the same name—a mistake, as I see it now, and one that was principally my own fault. For a while, we tried to distinguish between the two very different games by calling one ‘playground paddle tennis’ and the other ‘platform paddle tennis.’ But habits are hard to break, despite the fact that, in 1950, our game became officially ‘platform tennis’ when the Association changed its name. Despite the official change, it is still called—by most of the old-timers and many of the newcomers—paddle tennis.”
Source: Fessenden S. Blanchard, Platform Paddle Tennis, 1959, and 1950 Annual Meeting Minutes