Aggelos Bellos contributed to the JetBrains/phpstorm-stubs repository by addressing a documentation issue related to PHP 8.0 compatibility. He restored the documented availability of the DOMNode methods compareDocumentPosition and isEqualNode, ensuring that developers using PHP 8.0 or newer are not misled by outdated @removed tags. Working primarily with PHP and focusing on documentation accuracy, Aggelos committed the fix and updated the relevant files to reflect the correct method status. This targeted bug fix improved clarity for users of the stubs, reducing confusion and supporting a smoother development experience. The work demonstrated careful attention to detail and technical accuracy.