Apparently It Is a Word

[faustus]

De-duplicate.

"In order to de-duplicate effort and to ensure that we offer the best experience to all our users, the old telephone directory has been removed."

Comments

[drasecretcampus.livejournal.com]

That's fair enough. It hasn't made it into Chambers yet though.

People make much the same comments about - say - concretisation, sytagmatic and so forth in LitCrit. That too is technical talk, and not (necessarily) aimed at outsiders.

I don't think I'd object to reduplicate, mind. Deduplicate sounds too much like a stutter to me.