UAX #14 rev. 57, Section 5.1 class XX: unassigned code points outside CJK blocks are not all XX

The class XX description includes all unassigned code points that are not within a CJK block. The PR description in the same section puts unassigned code points of the Currency Symbols block in PR, and LineBreak.txt 18.0.0 gives most unassigned code points in U+1F000..U+1FAFF and U+1FC00..U+1FFFD the default ID.

Consequence

U+0061, unassigned U+1FAFF, U+0062: as XX (AL after LB1) no break on either side; as ID (data) a break on both sides, which is what LineBreakTest.txt and the published implementations give.

Proposed correction

Say that unassigned code points are XX unless the data file gives them another default, such as PR or ID.

Issued by

Unicode Consortium — Unicode Technical Committee

Act

UAX #14 revision 57 (Unicode 18.0.0)

Place

Section 5.1, class XX

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.

The XX line break class consists of all characters with General_Category Co as well as those unassigned code points that are not within a CJK block.

This class also contains all unassigned code points in the Currency Symbols block

How to check it without Arxo's tools

1. Open UAX #14 revision 57 (Unicode 18.0.0), Unicode Consortium and find Section 5.1, class XX. Compare the text with the quotation above. A copy is kept in this register: 296df5332aefe695-tr14-57.html (SHA-256 296df5332aefe695b4951b511288b118bc6a7b43db7fadfd60f6062096acc7c0, copy of the official file).
2. 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-2026-0461, https://arxo.io/findings/ARXO-2026-0461/ (status as of 2026-10-31). Data: ARXO-2026-0461.json.