Wong Shik Ling (also known as S. L. Wong) published a scheme of phonetic symbols for Cantonese based on the International Phonetic Alphabet (IPA) in the book A Chinese Syllabary Pronounced According to the Dialect of Canton.
The scheme has been widely used in Chinese dictionaries published in Hong Kong.
Other than the phonemic transcription system, Wong also derived a romanisation scheme published in the same book.
Hong Kong Education and Manpower Bureau formulates Cantonese romanisations based on the system.
Chinese phonology traditionally stresses finals because they are related to rhymes in the composition of poems, proses and articles.
Except /aː/ and /ɐ/, long and short vowels in Cantonese have complementary distributions and therefore do not function contrastively.
One particular aspect of the S. L. Wong system is the differentiation of the fricative and affricative initials into (/s/ /ts/ /dz/) and (/s2/ /ts2/ /dz2/) respectively to reflect the difference in Putonghua between (/x/ /q/ /j/) and (/s/ /c/ /z/), even though it was acknowledged that (/s2/ /ts2/ /dz2/) are "duplicates" of (/s/ /ts/ /dz/) and are pronounced exactly the same in modern Cantonese.
In classical Chinese, four basic tones are the level (平 ˌp‘iŋ), the rising (上 ˏsœŋ), the going (去 ˉhœy) and the entering (入 ˍjɐp).
Each tone's corresponding contour based on Yuen Ren Chao scheme in later studies is given in the second line of its table entry.