Any question answered...

Does it identify the model?

If I had to guess, I'd say the suffix identifies the tooling, of which there will be multiple sets for high volume items, either concurrently or sequentially. There are also codes which differentiate sprockets with the same tooth count depending on which sprocket is next in the sequence, e.g. there are two different 17T 5600 sprockets depending on whether the adjacent smaller sprocket is 15T or 16T.