Here, we're going to talk about the fret markers and the notes above the twelfth fret. Now, this guitar happens to have fret markers on the fret board itself--these dots. They are essentially, the odd numbered frets with the exception of fret one and fret eleven. So, this would fret three, fret five, fret seven, and fret nine, with the double-dot, being fret twelve, where this fret is the same as the open string letter names. Now you'll also see it the way I'm seeing it--looking down on the edge of the fret board there, are also the dots called, "fret markers". They allow you to see where you are if you're looking straight down on the neck, and not looking in this way. You can kind of get a little bit of each if you're holding the guitar right. Essentially, when you get to twelve, everything repeats itself. So the thirteenth fret is the same as the first fret, the fourteenth fret is the same as the second fret, as far as letter names go, but everything up here is an octave higher than the lower note equivalent. So, when you get to this one, it's going to be fifteen, it's going to be seventeen, and this would be nineteen--there's no dot, some guitars have a dot there in nineteen. If it had twenty-one frets, you might see a dot there too, and then, some guitars even go up to twenty-four frets, which would be the next octave, where you would see another double-dot.