Using single char variables is fine and IMHO leads to more concise code without sacrificing readability. When you are looping over a set, it's very common to think about it like `for all x in Xylophones do {...}`. For example in a nested loop, I would much rather prefer `i` and `j` over `iterativeAuxiliaryVariable1` and `iterativeAuxiliaryVariable2`. Never using single character variables as a "best practice" is just bad advice. As with pretty much everything in programming, the real answer is "it depends".