Here is a slight modification of @GerryMyerson's excellent answer, incorporating suggestions by @MattF., and @FrancescoPolizzi, transcribed from my comment at @MartinSleziak's suggestion: This site ...

Could this be the question you mean? It's not exactly about $i$ versus $-i$, but it mentions it as a motivating example. "Co-ordinate-free" mathematics for general structures? Even if it ...

As one of the people involved in the exchange from which you courteously elided names, I think that it's good to get rid of such links. Anyone who wants to find them can do so without our help. ...