Redundancy. Repeating yourself. Duplication. Copy-paste.
These have become like curse words in IT. This data is completely redundant! Did you just copy-paste that code?
We all learn early on in our programming ventures about how code duplication is bad. It creates maintenance nightmares we are told. Our code should be DRY. I believed it and lived by it. But as I am maturing in my programming I am more and more starting to doubt it.