The tag likely indicates a specific release group or encoding format — typically a high-quality 720p or 1080p rip, smaller in file size than a full Blu-ray remux, but better than standard SD rips. MicroHD releases are common among private trackers and P2P sites.
It seems you’re referring to the film (original title: 1492: La Conquista du Paradis ), directed by Ridley Scott and released in 1992.
