[andrewingram]

These files also generally work in a nested fashion, like .gitignore and the like. So you want something that can be injected into the namespace of any directory in your project with relatively low likelihood of conflicts.

[verdverm]

Not exactly (or unclear), .gitignore files combine, much like copilot files with glob or other matching. All the instructions are put into the context

> Agents automatically read the nearest file in the directory tree, so the closest one takes precedence

[radlad]

How about an underscore instead?

[globular-toast]

Fair. I didn't think about that.