LineBreak.txt 18.0.0: do the 85 unassigned code points in Supplemental Arrows-C default to ID, as the header says, or XX, as the data says?

The header of LineBreak.txt says all unassigned code points in U+1F000..U+1FAFF default to ID. In the data, 85 unassigned code points in Supplemental Arrows-C (U+1F80C..U+1F80F up to U+1F8D9..U+1F8FF) are XX, and LineBreakTest.txt uses U+1F8FF as XX.

Consequence

U+0061, U+1F8FF, U+0062: as XX there is no break; as ID there is a break on both sides.

Proposed correction

State which is intended for these code points and align the header or the data.

Issued by

Unicode Consortium — Unicode Technical Committee

Act

LineBreak.txt (UCD 18.0.0)

Place

file header, against the data for U+1F80C..U+1F8FF

Record

Question of reading or data

Class

Question of reading or data

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.

All unassigned code points in the following Plane 1 ranges, whether

inside or outside of allocated blocks, also default to "ID"

How to check it without Arxo's tools

1. Open LineBreak.txt (UCD 18.0.0), Unicode Consortium and find file header, against the data for U+1F80C..U+1F8FF. Compare the text with the quotation above. A copy is kept in this register: ae8cf1970c73f3f1-LineBreak.txt (SHA-256 ae8cf1970c73f3f1a12d77852df96c4b2b1723ca8b388e36bb5739250c6849de, 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-2026-0463, https://arxo.io/findings/ARXO-2026-0463/ (status as of 2026-10-31). Data: ARXO-2026-0463.json.