What is the syntax for an exclude pattern?

Advanced Solutions Static Code Analysis
1

The documentation for pio check --pattern says that you can specify what can be “included/excluded”, but any attempts to exclude some directories with either ! or -, whether enclosed in <> or not, have not been having the intended effect.

Is there a syntax for exclusion and does this feature even exist?

2

I suspect exclusion works by only specifying what to include, i.e. it’s implicit exclusion, not explicit. Since

By default only src_dir and include_dir are checked.

I would have though that if you only added patterns for the files/folders you want to check, only those would be added to the check process?