Oh, I see, those are abbreviations of words seperated by slashes. An odd form of annotation, I've never seen or used it before, myself. (I'm US American, BTW).

So if what was meant by that was "should of have gotten", then it's still incorrect. There is no "of" in that expression; people who say or write "of" are slurring the "have". It is only, "should have gotten" (or in that abbreviation style, "s/have/g").