What is the correct format for php.workspace.includePath?

On Windows, how do I specify an absolute path? do I need a drive letter?

I've tried using ../<file-to-include>.php as a test to include a file in the directory above the workspace, but it doesn't work. I also tried:

With no success. Any help would be appreciated.

Professor good question.

It's a semicolon (;) separated list of directories (not files).

The paths can be relative to the current workspace, or absolute (with <drive letter> prefix), or absolute with \ prefix.

Professor, note for others - this applies to Visual Studio Code.

Zed and other IDEs based on LSP (currently) require URI format, i.e. "file://<fullpath>".