These are all interesting and I would ilke to throw one more scenario in the mix. I created a pattern for a scarf to help promote a new yarn at the yarn shop I work at. I choose a stitch from the knitting encyclopedia decided on how wide and long. I then searched for a lace border stitch. The border I chose I thought belonged to someone and asked her permission to use it. She replied and said it was not hers but it was in the public domain so anyone could use it. I have been asked to sell my pattern is it okay?