Yi Syllables is a Unicode block containing the 1,165 characters (1,164 phonemic syllables plus 1 syllable iteration mark) of the Liangshan Standard Yi script for writing the Nuosu (or Northern Yi, Sichuan Yi) language.

The Sichuan Yi Pinyin romanization shown below is simplified using only basic Latin letters, and pronunciations are accurate for the major Liangshan dialect of the Nuosu (Northern Yi) language spoken in the Sichuan Province, where the syllabary was first standardized in 1974, based on its dominant Liangshan dialect spoken in that province and for which an extensive dictionary was developed and published in 1980:

• the initial consonants are noted with basic Latin consonants if possible, or distinctive consonant digrams rather than with extended consonants (e.g. from IPA symbols or basic Latin consonants with diacritics);
• the final vowels are noted with basic Latin vowels if possible, or distinctive vowel digrams rather than with extended vowels (e.g. from IPA symbols or basic Latin with diacritics); the vowel length is not noted but is implied for compound vowels; the actual phonetic vowel (e.g. noted 'i' in Pinyin) may be very different depending on the initial consonant; some vowels are noted using a digram with a final 'r';
• tones are noted after the final vowel by appending a 't' for the high tone, 'x' for the raising tone, 'p' for the low (or falling) tone, or their absence for the default mid tone (rather than with diacritics, digit-like modifier letters, or tone modifier marks); various Yi dialects spoken in China may use more than 4 tones for some syllables, but they are usually not semantically distinctive and unified using one of the 4 standardized tones (instead of the many existing variants or alternate logograms that were used in the Classical Yi logosyllabary). Another "Hani Pinyin" notation (also used in public displays, e.g. in the Yunnan Province for Southern Yi dialects) are noting tones with a trailing 'F', 'O', 'Q' or 'L' , instead of 't', 'x' or 'p' in Yi Pinyin: this alternate Hani Pinyin system also represents consonants and vowels with different single letters or digrams, but can distinguish more phonemic syllables than those unified in the current version of the modern Yi syllabary.
• Characters for the high tone (-t) are generally very different from those used for the low tone (-p), frequently based on a different radical. On the opposite, characters for the raising tone (-x) show an additional arc diacritic above the base character used for the similar syllable with the default mid tone, or above the character for the similar syllable with the low tone (-p) in 3 cases where there's no character for the mid tone in the standard syllabary).

Note that the name for U+A015 is a misnomer, as the character is actually a syllable iteration mark corresponding to "w" in standard Yi romanization.^[3] This error was not detected in the early phases of discussions for encoding the script and during the review even by Chinese members, because the character was not part of published syllabary charts but found only within some texts; the Pinyin romanization 'wu' was found only when citing the sign isolately, but in Mandarin reading, the Pinyin 'wu' is just reads as a long 'u', which would be confusive with the distinct Yi syllable encoded for 'u' alone, keeping the 'w' silent as a null consonant, so its Yi Pinyin romanization is written as 'w' only). This error has been later acknowledged by Unicode, but only after the final release of Unicode 3.0. As the character names already standardized in the UCS encoding is a character property that is subject to the Unicode Standard Stability Policy and that cannot be changed, a clarifying annotation was added into the lists of name aliases of the Unicode character database and in the published character charts.^[4] With this clarification, the general category property for this character was also changed from 'Lo' (other letter, used by all other Yi syllabic letters) to 'Lm' (as a letter modifier) and given an additional "Extender" property (like U+3005 IDEOGRAPHIC ITERATION MARK): these properties are not normative but are documenting for the best known practices about character behaviors and usages.