diff --git a/documentation/reference.md b/documentation/reference.md
index 0be51e6e3..eef59aa8f 100644
--- a/documentation/reference.md
+++ b/documentation/reference.md
@@ -352,6 +352,38 @@ Edit this one file, then `bun run build`.
 
 ## Data sources
 
+### ★ Persecution-safety — a rule about WHICH FIELDS a profile may carry
+
+Read this before adding a field or a link to any profile. **Some profiles are deliberately kept free of
+gospel/church/believer data, and a profile failing a "should have resource links" check may be OBEYING
+that rule rather than missing a feature.**
+
+The binding instance, stated in the code it governs (`plugin-designs/cities-internet/connectivity-list.vue`):
+
+> **PERSECUTION-SAFETY:** this profile carries connectivity + population + language only. It has **NO
+> gospel-resource, church or believer field and must not gain one.**
+
+Measured 2026-09-22: all three `cities-internet` profiles have **zero** `href` bindings, and the live leaf
+renders 1,567 nodes with **0 anchors**. That is correct. Its `source` field —
+`{name: "World Bank Open Data", url: "https://api.worldbank.org/v2"}` — is **API provenance**, not a
+user-facing destination, and it is surfaced as a citation paragraph when a region is expanded, which is the
+separate promise that header makes ("every figure carries its source, so the numbers can be audited").
+
+★ **Why this is written down here and not left in one file header.** A standing work item reads
+*"gospel-resources **+ cities-internet** maps must render with REAL resource links"* — one line batching two
+profiles whose contracts are opposite. `gospel-resources` genuinely renders 155 real eBible links; taking
+the same line literally for `cities-internet` means **adding a gospel-resource field to a profile whose
+header forbids exactly that**. A requirement that names two subjects deserves a per-subject check before
+anyone drains it.
+
+> **"Persecution-safe" is used for three different things in this repo** — don't assume one rule. Here it
+> means FIELD SEPARATION. In `key-cities/cities-list.vue` it means placename precision ("a wrong placename
+> in a persecution-sensitive dataset is the dangerous kind of wrong"). In
+> `research-dashboard/.../DashboardDataTable.vue` it means a dependency-free table (no third-party grid).
+> Only the first governs what data a profile may hold.
+
+---
+
 Maps read data through `@map/api/` driven by `library/api/sources.json`. Three source types:
 
 | Type | What | Points at |