Even though you're not allowed to actually copy and paste default markings onto your preset, you can still use them as a guide or a reference to help you get that marking. Just don't directly put the marking texture as a new layer on your preset file!
For example, it's just like with regular traditional art; don't put the finished artwork under the piece of paper and trace. Put the artwork and the piece of paper side by side and look at the artwork as you draw ^^