On Usenet, binary files are split into encoded text articles (often using ), usually with .partNN.rar files posted as separate multi-part posts. A "proper article" means correctly formatted headers, message IDs, and yEnc encoding so NZB downloaders like SABnzbd or NZBGet can reassemble the file.
It looks like you’re asking for a (or set of articles) for a split RAR part: ROYD-170-u.part12.rar . ROYD-170-u.part12.rar