Works of fiction with a military setting often use real ranks. However, sometimes, these just don't fit right. Maybe the aliens have to seem more alien, or maybe the setting is so completely different that real ranks just wouldn't fit, maybe it's a result of bad translation, regardless, the ranks are not the same as they are in Real Life. For real ranks, see Common Ranks, (usually) has nothing to do with Rank Inflation. Related to Random Power Ranking, which is for ranking Power Levels. Also related to Space Navy, which often uses one of these. See also Fantastic Honorifics, which can overlap.