The word retainer has an appealing mercenary quality to it. The dream is that your knowledge of an esoteric system set up in the 1980s gets you warehoused in a data closet at a mid-sized organization, where you can spend the rest of your days browsing Hacker News and watching pirated films.
After 3 years the finish gets dull, but it’s still not bad. Not the worst contract I ever worked.