On the flyleaf was a rubber-stamped grid, with words and symbols written on the lines. This is a textbook, he thought. Those must be the student's names or symbols. There was a familiar-looking mark on one of the lines—a pair of dolphins. Wasn't that what the pony who'd recovered my glasses had for a mark? Maybe this used to be her book, he thought, flipping it open. I wonder why they sometimes use the mark and sometimes don't? Maybe the non-unicorns aren't as good at drawing a legible symbol. I seem to remember that one of the first things I learned at school was how to write my name, but it took a while before it was readable.