Some PHP error codes not shown in Problems but marked in editor

Sorry, I just started using the probelms window and I couldn't find the answer in the doc.

Codes like 7101 or 6612 are marked in the editor, but not in the problems windows. Where it is defined which codes get displayed in the list?

I know now how to exclude, but not how to include more?

Thank you for the question.

Those have low severity by default, marked as "hint" only. VSCode does not list hints in the Problems window.

You can set a higher severity using .editorconfig file:

[*.php]
php_diagnostic_php6612 = warning