diff --git a/PENDING.md b/PENDING.md
index 1db0100..84da7bb 100644
--- a/PENDING.md
+++ b/PENDING.md
@@ -6677,3 +6677,33 @@ Three independent narrowings, none of them declared: the header regex is `REVIEW
 
 **Files affected:** `scripts/governance-drift-check.py` (`RE_HEAD`, `RE_AMENDS`, `register_findings`, its four controls, and the call site at L241).
 **Awaiting:** Steward authorization.
+
+---
+
+### PENDING-173 — ADDENDUM 1: the census was under-counted twice, and 48 of 81 blocks carry no item number at all
+**Date:** 2026-08-31
+**Placement note:** appended at the end rather than inserted beside PENDING-173's body, following the precedent set by PENDING-164 AMENDMENT 2 earlier today — inserting mid-file is what silently changed the line numbers a checker was reading on 2026-08-27 (PENDING-104 ADDENDUM 1). The disposition is PENDING-110's to settle; no scheme is proposed here.
+**Filed under:** the jurist ruling of 2026-08-31 (`claude/governance/PENDING-172-173-JURIST-RULING-2026-08-31.md`), REVIEWED-132 draft **condition 3** — *"the acceptance check enumerates, it does not count … If the two disagree, the disagreement is the finding and is reported, never reconciled by amending the table."* The ruling is **not placed**; this addendum is filed under executor authority for a `[HARDENING]` item, and reports the disagreement rather than acting on the ruling.
+
+**⚠ THE DISAGREEMENT, REPORTED AND NOT RECONCILED.** PENDING-173's table asserts **16** amendment-shaped blocks. Running the enumeration the condition requires returns **81**.
+
+| register | `##` ITEM-N — MARKER | `###` ITEM-N — MARKER | compound | `###` MARKER, **no item number** | in-body | total |
+|---|---|---|---|---|---|---|
+| `PENDING.md` | 10 | 13 | 2 | **48** | 2 | **75** |
+| `PENDING-archive.md` | 0 | 0 | 1 | 0 | 0 | 1 |
+| `REVIEWED.md` | 3 | 1 | 1 | 0 | 0 | 5 |
+
+⇒ the control sees **3 of 81**, not 3 of 16. The table in PENDING-173 stands as filed and is wrong; it is left standing, per the condition.
+
+**Why it was wrong twice, both times in the same direction.** The first census matched one header form (`^## PENDING-N — AMENDMENT`) and returned 3. Corrected to include `ADDENDUM`, it returned 16. Both passes assumed `##`. The register also uses `###` for blocks placed beside their parent, and — the case neither pass imagined — **a bare `### AMENDMENT k — date` with no item number**, which is the single most common form in the file. **Each correction was made by widening the pattern I had guessed, never by enumerating what the file contains.** That is the same failure the item reports in the instrument, committed twice by the item's own author while reporting it.
+
+**⚠ THIS DEFEATS OPTION (a) AS SUFFICIENT, WHICH IS THE ITEM'S OWN RECOMMENDATION.** A widened parser can *find* all 81. It cannot *attribute* 48 of them: an unnumbered `### AMENDMENT 1 — 2026-08-08` names no parent, so it can only be assigned by "the last `##` header above it". REVIEWED-132 draft condition 1 requires `originals` to default to not-original on an unrecognized marker — but an unnumbered block has **no number to test against `originals` at all**. The condition cannot be satisfied for 59% of the corpus by parser work alone.
+
+**And position is not a reliable substitute.** Among the unnumbered blocks the marker numbers run, in file order, `… 5 · 8 · 6 · 7 · 8 …`, with two blocks both reading `AMENDMENT 8` at different dates. Either they belong to different parents — in which case the marker number alone is ambiguous file-wide — or one sequence is out of order. **An id-keyed reader cannot decide which**, and this addendum does not claim to know; establishing it requires reading the 48 blocks, which is not done here.
+
+**⇒ The routing in REVIEWED-132 draft condition 5 is strengthened, not weakened.** The jurist routed the *convention* question to PENDING-146 and authorized only the parser widening. This enumeration says the parser widening is **necessary and demonstrably insufficient**: 48 blocks are unattributable without a prospective convention that requires a parent id on every new amendment block. The recommendation in PENDING-173 — option (a) — is corrected to **(a) as the owed floor, not as the fix.**
+
+**⚠ What this addendum does not establish.** Whether any of the 81 blocks actually replaced the record it amends. The enumeration counts blocks by surface form; it does not read them. The latent false-negative described in the parent remains latent and unmeasured, now across a corpus five times larger than the parent believed.
+
+**Files affected:** unchanged from the parent.
+**Awaiting:** Steward authorization (with the parent).