Recently I found myself in a situation where I was unsure about comma usage. The sentence was Cereals can be extremely nutritious, for example, Frosted Flakes.
Now is the usage of the comma before and after for example incorrect? I am not particularly concerned about whether or not there is a better way to rephrase the sentence, but I want to know whether it is grammatically correct for me to place the commas there or not. If so, can somebody explain why.