: These are likely internal catalog or file reference numbers used by content distributors or indexers.
Regarding the specific details of the production, these releases are categorized within the Japanese Adult Video (JAV) industry, where content is organized by unique production codes like the one provided. General Context China Miyu -ONED 858- Avi 019
Utilizing high-resolution digital cameras to differentiate their "amateur" style from lower-quality competitors. : These are likely internal catalog or file