For copyright notices, or trademarks it is customary to include the appropriate signs:
Symbol Entity Example Copyright sign © Copyright © 1999 W3C Registered trademark ® MagiCo ® Trademark ™ Webfarer™
Note HTML 4.0 defines ™ for the trademark sign but this is not yet as widely supported as ™
There are a number of other entities you may find useful:
Symbol Entity Example Less than < < Greater than > > Ampersand & & nonbreaking space em dash — — quotation mark " "