Occasionally some of our clients receive editorial mentions and links in which the author adds utm parameters to the outbound links on their blog. The links are always natural, never compensated, and followed.  However, they are sometimes listed as utm_source=affiliate even thought we have no existing affiliate relationship with the author.  My practice has been to ask the author to add a rel="norewrite" attribute to the link to remove any trace of the word affiliate. I have read that utm parameters do not affect link juice transfer, however, given the inaccurate "affiliate" source, I wouldn't want Google to misunderstand and think that we are compensating people for followed editorial links. Should I continue following this practice, or is it fine to leave these links as they are? Thanks!