There have been many attempts to reconstruct the sounds or phonemes of the Qieyun system, conventionally called Early Middle Chinese, yielding a series of alphabetic transcriptions. Each of these is disputed to some extent, and many scholars doubt that the system corresponds to any single form of speech. The custom in Chinese scholarship is to neutrally describe a syllable with a string of six characters identifying its 攝 shè, whether it is 開 kāi or 合 hé, the division, tone, Guangyun rime and initial. Needing a reference point for his reconstruction of Old Chinese phonology, Baxter designed an alphabetical presentation of the same information, rather than a reconstruction. His system is a significant simplification of the Karlgren–Li reconstruction of Middle Chinese, but retains a similar structure, especially in the treatment of medials and vowels.
Initials
Baxter's transcriptions of the traditional initials are as follows: Notes:
-r-, -y- and -h- do not represent separate segments, but retroflex, palatalized and aspirated articulation respectively of the preceding consonant.
The initial h- represents a voiced fricative while x- represents its voiceless counterpart.
In the rime tables, the palatal allophone of 云 is combined with 以 as a single initial 喻.
Finals
Finals with vocalic endings could occur in the level, rising or departing tones; the few that occurred only in the departing tone are marked with -H in the following table. The chóngniǔ doublets of division III finals are not distinguished in the traditional categories. Adopting a purely notational device of Li Fang-Kuei, Baxter used the spelling -ji- for finals occurring in the fourth row of the rime tables, retaining -j- for those occurring in the third row. The -j- of division III finals is omitted after palatal initials, which end in -y-. Finals ending in nasals -m, -n and -ng could occur in the level, rising or departing tones, with parallel finals ending in -p, -t and -k placed in the entering tone.
Tones
The rising tone is marked with a trailing X, the departing tone with a trailing H. The level and entering tones are unmarked.
