Clarify how artifacts:untracked works

doc/ci/pipelines/job_artifacts.md

@@ -194,7 +194,8 @@ artifacts:
 ### Add untracked files to artifacts
 
 Use [`artifacts:untracked`](../yaml/index.md#artifactsuntracked) to add all Git untracked
-files as artifacts (along with the paths defined in [`artifacts:paths`](../yaml/index.md#artifactspaths)).
+files as artifacts (along with the paths defined in [`artifacts:paths`](../yaml/index.md#artifactspaths)). Untracked
+files are those that haven't been added to the repository but exist in the repository checkout.
 
 Save all Git untracked files and files in `binaries`:
 

doc/ci/yaml/index.md

@@ -939,7 +939,7 @@ rspec:
 
 Use `artifacts:untracked` to add all Git untracked files as artifacts (along
 with the paths defined in `artifacts:paths`). `artifacts:untracked` ignores configuration
-in the repository's `.gitignore` file.
+in the repository's `.gitignore`, so matching artifacts in `.gitignore` are included.
 
 **Keyword type**: Job keyword. You can use it only as part of a job or in the
 [`default` section](#default).