docs(C1): a particle that is also a credential counts in the run (#554)

[derek73]

Closes #554 by choosing option (a), which is what the parser already does. No parse changes.

After a comma, a word that is both a particle and unambiguous suffix vocabulary (vd, mc) still counts as a suffix word in C1's run test. S2's company rule still won't let that word vouch for the word behind it. The issue treated this as two rules giving different answers to one question. It's actually two different questions:

• Run membership asks what the word is. vd is unambiguous suffix vocabulary.
• Company asks whether the word vouches for the word behind it. A particle can't, because P2 joins it forward to exactly that word.

Evidence. Neither reading of vd Ma after a comma is realistic, so the mixed-case form decides nothing. Uniform case is where the decision matters, because there are no capitals for S2 to read and the vocabulary is the only signal. There the part reads as the credential run, which is the reading a person would take:

text	reading on master
John Smith, vd Ma	suffix vd Ma, reports suffix-or-name
JOHN SMITH, VD MA	suffix VD MA, reports suffix-or-name
john smith, vd ma	suffix vd ma, reports suffix-or-name

mc reads the same way in every casing. This is also what 1.4.0 read; 2.0.0 through 2.3.0 read the whole name as the family. Option (b) would have needed a particle exception in C1 and in #567's paired-initials check. Its result would be the family JOHN SMITH VD MA with no given name. #563's site (García Márquez, vd G.J.) reads exactly like PhD G.J., so it needs no change.

Changes

• rules.md#C1: a clause saying a word's particle reading doesn't take it out of the run. It is scoped to the unambiguous suffix vocabulary, which is exactly {vd, mc}. New examples pin the reading and the report for vd Ma / VD MA, and contrast John Smith, Jr vd (silent) with John Smith, Jr do (reports, because do is in the ambiguous half and already counts as a class word).
• decisions.md#C1: a dated entry for Should a particle that is also a credential (vd, mc) count in a credential run after a comma? #554 with the evidence and a recompute recipe. It points to Why does SMITH VD MA, JOHN read family SMITH MA with VD as a suffix? #573.
• The new example names are added to the rules corpus. The Should a credential run after a comma keep its comma when the last word is an ambiguous acronym? John Smith, PhD MEng reads first PhD, last John Smith #544 run rule in the 2.0.0–2.3.0 ledgers gains John Smith, vd Ma, JOHN SMITH, VD MA and John Smith, Jr do, with each baseline's own reading in the comment, and the _CORPUS_CLAIMS entries they move are re-recorded.

Follow-up

#573 covers the uniform-case defects found while measuring this. In SMITH VD MA, JOHN, VD is pulled out from between the family words. In DOE, JANE PHD VD MA, VD lands in front of the family name. In SMITH, VD MA, VD stays behind in the family. That issue also covers #554's aside about Doe, Jane PhD vd Ma going into middle without a report.

Verification

• Full suite: 10626 passed. ruff check is clean.
• The differential gate exits 0 at 1.4.0, 2.0.0, 2.1.0, 2.2.0 and 2.3.0, with 0 unexplained. The radar-unclassified counts are the same as before this change.
• Review: a design-docs-reviewer pass before the PR, then /pr-review-toolkit:review-pr (code, comments, tests), then a second review of the fix commit. No parse claim was wrong. The rounds fixed the clause's wording and scope, added the pinning examples, and corrected one history claim: the Smith vd Ma, John split shipped in 2.2.0 and 2.3.0 and was fixed by Case and shape decide a bare ambiguous credential acronym (#289, #516) #530, not only inside fix(#544): a credential run keeps its ambiguous members #552.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.87%. Comparing base (fc682e3) to head (372d5ec).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #574   +/-   ##
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  Coverage   98.87%   98.87%           
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  Files          45       45           
  Lines        3990     4017   +27     
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+ Hits         3945     3972   +27     
  Misses         45       45           

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