diff --git a/docs/technical-notes-codex.md b/docs/technical-notes-codex.md
index 93a52f8..dbacd80 100644
--- a/docs/technical-notes-codex.md
+++ b/docs/technical-notes-codex.md
@@ -1,6 +1,6 @@
 # Technical Notes (Internal)
 
-Last updated: 2026-02-16
+Last updated: 2026-02-19
 
 ## Purpose
 Internal technical snapshot of the `backupchecks` repository for faster onboarding, troubleshooting, and change impact analysis.
@@ -121,7 +121,8 @@ Critical deletion order to avoid constraint violations:
 - DSM Updates, Account Protection, Firmware Updates
 - Set appropriate backup_type (e.g., "Updates", "Firmware Update")
 - Do NOT participate in schedule learning
-- Still visible in Run Checks for awareness
+- Usually still visible in Run Checks for awareness
+- Exception: non-backup 3CX informational types (`Update`, `SSL Certificate`) are hidden from Run Checks
 
 **Regular Parsers:**
 - Backup jobs (Veeam, Synology Active Backup, NAKIVO, etc.)
@@ -202,7 +203,10 @@ All pages use **explicit link-based queries** (no date-based logic):
   2. Job-level scope: `tickets JOIN ticket_scopes WHERE job_id = Y AND resolved_at IS NULL AND active_from_date <= run_date`
 - Prevents duplicates by tracking seen ticket IDs
 - Shows newly created tickets immediately (via scope) without waiting for resolve action
-- Same for remarks: `remarks JOIN remark_job_runs WHERE job_run_id = X`
+- **Two-source remark display**:
+  1. Direct links: `remarks JOIN remark_job_runs WHERE job_run_id = X`
+  2. Job-level scope: `remarks JOIN remark_scopes WHERE job_id = Y AND resolved_at IS NULL AND active_from_date <= run_date` (with timezone-safe fallback from `start_date`)
+- Prevents duplicates by tracking seen remark IDs
 
 ### Resolved vs Deleted
 - **Resolved**: Ticket completed in Autotask (tracked in internal `tickets.resolved_at`)
@@ -359,6 +363,23 @@ File: `build-and-push.sh`
 
 ## Recent Changes
 
+### 2026-02-19
+- **Added 3CX Update parser support**: `threecx.py` now recognizes subject `3CX Notification: Update Successful - <host>` and stores it as informational with:
+  - `backup_software = 3CX`
+  - `backup_type = Update`
+  - `overall_status = Success`
+- **3CX informational schedule behavior**:
+  - `3CX / Update` and `3CX / SSL Certificate` are excluded from schedule inference in `routes_shared.py` (no Expected/Missed generation).
+- **Run Checks visibility scope (3CX-only)**:
+  - Run Checks now hides only non-backup 3CX informational jobs (`Update`, `SSL Certificate`).
+  - Other backup software/types remain visible and unchanged.
+- **Fixed remark visibility mismatch**:
+  - `/api/job-runs/<run_id>/alerts` now loads remarks from both:
+    1. `remark_job_runs` (explicit run links),
+    2. `remark_scopes` (active job-scoped remarks),
+  - with duplicate prevention by remark ID.
+  - This resolves cases where the remark indicator appeared but remarks were not shown in Run Checks modal or Job Details modal.
+
 ### 2026-02-13
 - **Fixed missed runs ticket propagation**: Added `link_open_internal_tickets_to_run` calls in `_ensure_missed_runs_for_job` (routes_run_checks.py) after creating both weekly and monthly missed JobRun records. Previously only email-based runs got ticket linking, causing missed runs to not show internal tickets or Autotask tickets. Required `db.session.flush()` before linking to ensure run.id is available.
 - **Fixed checkbox auto-selection**: Added `autocomplete="off"` to all checkboxes on Inbox and Run Checks pages. Prevents browser from automatically re-selecting checkboxes after page reload following delete actions.