diff --git a/.claude/rules/pr-body-contract.md b/.claude/rules/pr-body-contract.md
index 1fb7884..f913068 100644
--- a/.claude/rules/pr-body-contract.md
+++ b/.claude/rules/pr-body-contract.md
@@ -1,11 +1,14 @@
 # PR body contract
 
-The `pr-contract` step inside `ci-status` fails a pull request only on a
-non-Conventional-Commits title or a `do-not-merge` label. The body contract is
-advisory, reported by comment and the `needs-issue-linkage` label, but
-expected: open with `Closes #<issue>` (or `Fixes`/`Resolves`), a
-`Refs: #<issue>` line to link without closing (never "does not close", which
-still closes), or `No related issue: <reason>`, then fill `## Summary`,
-`## Fix`, `## Verification`, and `## Related`. Draft from the repo's PR
-template (else the `melodic-software/.github` default); canonical record:
-`components/pr-convention-policy/policy.json` in `melodic-software/standards`.
+The `pr-contract` step inside `ci-status` fails a pull request on a
+non-Conventional-Commits title or a `do-not-merge` label, and, in repositories
+that enable it, on a body line that would start with the word `committer` after
+the 72-column squash wrap, which breaks the squash commit's signature: reword
+that line. The body contract is advisory, reported by comment and the
+`needs-issue-linkage` label, but expected: open with `Closes #<issue>` (or
+`Fixes`/`Resolves`), a `Refs: #<issue>` line to link without closing (never
+"does not close", which still closes), or `No related issue: <reason>`, then
+fill `## Summary`, `## Fix`, `## Verification`, and `## Related`. Draft from
+the repo's PR template (else the `melodic-software/.github` default);
+canonical record: `components/pr-convention-policy/policy.json` in
+`melodic-software/standards`.