UAX #29 rev. 49, Section 4.2.6: modifier symbols are said not to be ALetter, but 58 of them are

Section 4.2.6 says that modifier symbols (General_Category Sk) are not in the ALetter class and so cause word breaks by default. WordBreakProperty.txt 18.0.0 gives Word_Break=ALetter to 58 Sk code points, and Table 3 of the same annex lists them by name in the ALetter row.

Consequence

U+0061, U+02D2 MODIFIER LETTER CENTRED RIGHT HALF RING, U+0062: the sentence gives breaks on both sides of U+02D2; the data and WB5 give one word.

Proposed correction

Say “Most modifier symbols (General_Category = Sk) are not in the ALetter class”.

Issued by

Unicode Consortium — Unicode Technical Committee

Act

UAX #29 revision 49 (Unicode 18.0.0)

Place

Section 4.2.6, against Table 3

Record

Discrepancy

Class

Text of the act

Where it arose

The text of the act

Arxo's conclusion

Confirmed

Official text

Unchanged at last check

Last checked

2026-10-31

Evidence

Contradiction within the text. Quotations are verbatim from the official material; translations are ours and marked.

Modifier symbols (General_Category = Sk) are not in the ALetter class and so do cause word breaks by default.

02D2..02D7 ; ALetter # Sk [6] MODIFIER LETTER CENTRED RIGHT HALF RING..MODIFIER LETTER MINUS SIGN

ALetter | Alphabetic = Yes, or any of the following characters: U+00B8 ( ¸ ) CEDILLA U+02C2 ( ˂ ) MODIFIER LETTER LEFT ARROWHEAD ..U+02C5 ( ˅ ) MODIFIER LETTER DOWN ARROWHEAD

How to check it without Arxo's tools

1. Open UAX #29 revision 49 (Unicode 18.0.0), Unicode Consortium and find Section 4.2.6, against Table 3; Table 3, row ALetter. Compare the text with the quotation above. A copy is kept in this register: 60fb49ee640a154d-tr29-49.html (SHA-256 60fb49ee640a154d9e40468306c6b283edcef73be3af5ede778107b4787bdec8, copy of the official file).
2. Open WordBreakProperty.txt (UCD 18.0.0), Unicode Consortium and find WordBreakProperty.txt (UCD 18.0.0). Compare the text with the quotation above. A copy is kept in this register: 8dbfa17063e11084-WordBreakProperty.txt (SHA-256 8dbfa17063e11084201f33c3e76d485d3b9166930c71db8e39ed1c9234171aec, copy of the official file).
3. The finding holds if the quoted passages read as shown and the comparison gives the result stated at the top of this page. If it does not, write to us with the record ID.

How this finding was made

AI agents read the annexes and the data files and compared them; the examples were run through published implementations. An AI coordinator checked each place against the full annex and the trackers, and two further AI models checked the report before filing.

Responsible institutions

• Unicode Consortium — publishes the annex and the Unicode Character Database

Reported to

Responses

No response recorded.

History

1. 2026-10-31Confirmed by Arxo
2. 2026-10-31Entered in the register
3. 2026-10-31Reported to Unicode Consortium (e-mail)

Cite this record

Arxo Law, Arxo Findings Register, ARXO-2026-0459, https://arxo.io/findings/ARXO-2026-0459/ (status as of 2026-10-31). Data: ARXO-2026-0459.json.