Trademark Attorney Riddle, with Esquiretrademarks.com, wrote an educational article explaining Trademark Disclaimers. 

What is a Trademark Disclaimer?

A trademark disclaimer is a written statement that “disclaims” “exclusive rights” to “unregisterable content” in a “trademark registration”.

A Disclaimer Only Limits Rights Conveyed by the Trademark Registration – Common Law Trademark Rights Are Unaffected.

For more, visit Trademark Disclaimer