Would a See also: Redundant link be inappropriate?
- No, but it would be redundant! :)
Item "1. Superfluous; exceeding what is necessary." is not exactly true in systems design where devices or features are purposely replicated to allow one to operate if another fails. These added features are not superflous or unnecessary to meet the design goals of the system.
Thus, either another definition should be added -- viz. "A device or feature that is replicated in a system such that one can take the place of another if the first one fails."
Or, at least insert the word "absolutely" ahead of "necessary" in 1.