H.Ä.Jaschke views the retroflex letters as the same positions and layers as base letters in his A Tibetan-English Dictionary, however he only collects two of them, and gives the order like ᅉ(tt), (dd), ࿖(t), ᅊ(tth).
[8] to say, the Tibetan-transliterated letters emerge prior to Tibetan letters in the sequence of dictionary entries.