In the context of, say, aerodynamics, its merely a word of art, e.g. http://dictionary.reference.com/browse/aerodynamic+braking
It'll be another word, perhaps in a more ambigious context, next time. Which brings up another point: I just don't want to have to worry about what will become this politically incorrect in the future when I'm writing code and documentation.
This patch retards the rate of retry attempts after three consecutive failures
We live in a world where a guy wants to ban Mel Brooks' The Producers because he doesn't realize it's a satire of Hitler, not an homage. Lots of people don't or won't appreciate context.
re: The Producers, with any topic you'll get one or two extremists of any varity. You should judge it not by "did someone want to stop this", but instead by "did someone(s) in power to stop it, want to stop it". One crank protesting outside a cinema is very different from the CEO of a movie studio deciding not to make the film.
Then don't say/write bigotted things. Honestly, it's like asking people not to write spelling or grammar mistakes in documentation. It's not that hard.
It's not "these 6 letters in this combination is banned", it's "stop insulting people based on mental illnesses".
In the context of medication, "retard" is still in use: it describes medication that is released steadily and continuously into the bloodstream.