The very first RY liquid was created in a single afternoon by two men: Ludo, one of the owners of Janty, and a Chinese flavor chemist, presumably working for Dekang. They started in the lab of a Dekang factory in China with some basic flavors they both agreed on and made various "test juices," tweaking the recipe along the way. After about four hours, they came up with the one they liked best, and they christened it
Ruyan 4---"Ruyan" being Chinese slang for "cigarette-like" and "4" because that was the fourth version they made that afternoon. Soon after, the name was abbreviated to
RY4.
Janty began marketing that formula in 2007 and still sells the original recipe as RY4 in their Elixir line. Dekang modified the original recipe (removing the slight sourness of the Janty original recipe and changing the proportions of flavoring for a slightly sweeter taste) and produced numerous variations of RY4 for their own label, including the now-mythic "lost" Dekang RY4, the recipe for which was stolen by a departing flavor chemist who was leaving to start his own
juice company. That recipe remains missing to this day. The chemist was subsequently arrested, tried, and is serving a prison sentence in China.
RY1, 2, and 3 were all reverse-engineered much later by Dekang (and by Hangsen as well), but Janty RY4 was the first and original
tobacco/caramel/vanilla blend called RY.
At any rate, that's the gist of the story we unearthed from Ludo and other inside sources on
The Really Big RY4 Roundup thread.
The point is that RY4 came first. RY3, RY2, and RY1 were created afterwards, almost like "prequels" in the movies (think Star Wars).