Support for Private Windows
Inspired by the following post.
The Chromium team has an existing protocol as found on the Chrome Git repository post.
I'm looking for the possibility to tag specific surfaces with a "private" or "secure" tag. This tag would prevent screencasting applications the ability to capture the app's graphics. This could be useful when the entire screen is being captured and an application like a password manager gets opened, where a leak could be disastrous.
I'm unsure if wayland, the x-d-p permission store, or both would be the right place for this, as it would be preferred for apps to hint this themselves while also allowing users the option to forcefully disable (or enable) this hint on a per-app basis.
I know Windows does this already in some way to prevent videos with DRM from being captured. It blocks the capturing and replaces it with a complete black screen. This seems to be done with the parameter found here.
Edit: OBS has implemented something like this for Mac. It gives an option to hide to OBS window from being recorded, to hide stream settings being changed or to hide the mirror effect.
Discord also has implemented a similar option in their software when Streamer Mode is enabled: "Hides most Discord windows from most screen capturing software."