MINC tag refers to a file format and/or a library for storing named, multi-dimensional variables in files in a machine-independent way.
Quote from reference:
The MINC file format (Medical Image NetCDF) is based on the NetCDF file format (Network Common Data Form) distributed by the Unidata Program Center. NetCDF provides a software interface for storing named, multi-dimensional variables in files in a machine-independent way. This interface removes applications from the concerns of portability and file structure and encourages a self-describing form of data.