User blog comment:MTV/Captain Marvel/@comment-1212133-20100730224754

Yes you'd have to either rename the character or only call them by their real names within the confine of the book, but not on the cover or ads because that would infringe on their trademark. Ex. The name Daredevil is trademarked by Marvel, but Golden Age Daredevil is public domain. So, comic companies renamed the character Red Devil, Death Defying 'Devil, Double Dare, etc. or like Eric Larsen did in Savage Dragon only called him Daredevil in the comic.