This specific alphanumeric code is part of a standardized cataloging system used by Japanese media producers to identify their releases.
Media under this label is part of the adult entertainment industry.
Be cautious when searching for or downloading files with this naming convention. MP4 files found on untrusted peer-to-peer sites or unofficial forums often serve as "clickbait" to distribute malware, trojans, or unwanted browser extensions.
The prefix "IPX" identifies the production studio and the series, while the number refers to the specific entry in their library.