Data file used by Celestia, a free universe visualization program; saves a list of positions and timestamps as well as velocities for each position; used for defining the location and trajectory of entities, such as planets, moons, and stars.
XYZV files are saved in a plain text format, but they are not commonly created manually. Instead, they are often generated by universe trajectory algorithms.
XYZV files are often referenced by .SSC catalog files, which define space entities. Any XYZV files that are referenced by an SSC file must be saved to a \data\ directory within the directory that the SSC file resides. For example, if cassini.ssc is stored in the \extras-standard\cassini\ directory, then all cassini XYZV files should be stored in the \extras-standard\cassini\data\ directory.