For example, on TokenTest.php, the summary is the following one.
@coversDefaultClass \Drupal\Core\Utility\Token[[api-linebreak]] @group Utility
[[api-linebreak]] should not appear.
The documentation page for the class, TokenTest, correctly replaces [[api-linebreak]] with a line break.
Yet, on the same page, [[api-linebreak]] appears again.
It seems like, when the text is formatted as single line, [[api-linebreak]] is kept instead of being replaced with a space.
Active
2.0
User interface
The [[api-linebreak]] part is added by Formatter::cleanComment(). I still have to figure out which method should remove that part, to be able to provide a merge request.
Thanks for reporting. The issue here is that the reported parts where it shows are views. So we might need to add a preprocess field hook or similar.