I am ashamed to say that I had probably about 4 dozen eggs stacked up everywhere I have no idea which end were the fresh ones and which were the oldest so I boiled the whole lot of them and started over with the 4 that gathered so far today. I remember there being a taboo against marking eggs for hatching, but what about eating? I could use pencil but it's too light and can get rubbed off...so I used a sharpie. Think there will be a problem with that? It's only 4 eggs, so far so I can always dispose of them and start over with pencil, but I just wanted to get some opinions.