Strange behavior of the Glossary App

Hi!

Today I discovered 89 deleted pages in the, whose name ends with a “Glossary”.
What is strange:

  1. These pages have never been added to the Glossary App.
  2. These pages can not be deleted manually or by scripts.
    %D0%B7%D0%BE%D0%B1%D1%80%D0%B0%D0%B6%D0%B5%D0%BD%D0%BD%D1%8F

Tell me, please, what is it?

Thanks.