diff --git a/docs/04-theming-and-users.md b/docs/04-theming-and-users.md
index c7931f3..2c2ea28 100644
--- a/docs/04-theming-and-users.md
+++ b/docs/04-theming-and-users.md
@@ -254,6 +254,45 @@ about to POST branding for any reason, GET `/System/Configuration/branding`
 first and confirm the override block matches the §3a skeleton before
 sending.
 
+### 3c. Header icon hide (2026-05-08): keep search, drop SyncPlay/Cast/User-menu
+
+Top-right header had four buttons: SyncPlay (Create Group people-pair),
+Cast (Chromecast triangle), Search (magnifying glass), User (account menu).
+Goal: hide everything except Search. Selectors confirmed by grep against
+the live JF 10.10.3 web bundle (`73233.*.chunk.js`): `headerSyncButton`,
+`headerCastButton`, `headerSearchButton`, `headerUserButton` (also
+`headerAudioPlayerButton` for the now-playing badge). Each is a class on
+the `<button>` element, not an id, so the hide rules target the class
+directly. Pure CSS appended to existing `CustomCss` via the standard
+GET → edit → POST flow (no container restart, no `index.html` edit):
+
+```css
+/* Hide top-right header icons (keep Search) — 2026-05-08 */
+.headerSyncButton { display: none !important; }
+.headerCastButton { display: none !important; }
+.headerUserButton { display: none !important; }
+```
+
+Rationale per button:
+- **headerSyncButton** — SyncPlay group creation. Single-user / family box,
+  no co-watching workflow yet (see §5b for the full SyncPlay context).
+- **headerCastButton** — Chromecast picker. No Cast targets on this LAN,
+  the button just opened an empty device list.
+- **headerUserButton** — account/sign-out drop-down. Non-admins lose almost
+  every entry in this menu after §4 lockdown anyway, and admins use the
+  Dashboard wrench. Removing the icon eliminates the dead-end click.
+- **headerSearchButton** — kept. Only navigation affordance left in the
+  top-right. The CSS does not touch `.headerSearchButton` so its event
+  handler is untouched and the icon still triggers the search drawer.
+- The hamburger drawer toggle on the LEFT (`.headerHomeButton` /
+  `.mainDrawerButton`) is also untouched.
+
+Verified post-write via `GET /Branding/Configuration` that all earlier
+rules are still present (Cineplex `@import`, cast/crew hide, ARRFLIX
+logo override, Quick Connect hide, Settings drawer hide, LoginDisclaimer,
+SplashscreenEnabled). POST returned 204; same operational rule from §3b
+applies — this was the last branding POST in the sequence.
+
 ---
 
 ## 4. Multi-user UX prep