Notifications contain extras (title, text, image). The VISIBILITY_SECRET flag allows the system to show the app icon but redact the payload text on a secure lock screen. This is crucial for 2FA (Two-Factor Authentication) codes, preventing bad actors from viewing OTPs without unlocking the device.9
Micro-Blog Draft:
Title: Hide Your Text Messages on the Lock Screen
The Problem: You don't want people reading your texts or 2FA codes just by looking at your locked phone.
The Fix: Redact sensitive content until you unlock the device.
Step-by-Step Guide:
Go to Settings > Notifications.
Tap on Notifications on lock screen.
Select Show sensitive content only when unlocked (or "Hide content" on Samsung).
Now, your phone will ding and show "WhatsApp" or "Messages," but the actual text will be hidden until you use your fingerprint.14
