This area has been discussed heavily in all types of content related to the two major cases : Redskins and Tam. For sake of easy use all that content has not been linked. Please use a search engine to find content discussing those two cases.
The USPTO’s tribal insignia database (which helps ensure that Native American images are not appropriated as trademarks (Continuously updated)
Six Dr. Seuss Books to No Longer Be Published, Due to Racist, Insensitive Imagery Hollywood Reporter (2021)
Fifa's 'hardline approach' at World Cup will be to take the money and run Ruling body still seems to care more about ambush marketing and trademarks infringement than racism and homophobia My Sports Analysis (2018)
MacKay, J., RACIST TRADEMARKS AND CONSUMER ACTIVISM: HOW THE MARKET TAKES CARE OF BUSINESS. 42 Law & Psychology Review 131 (2018).
Swastika, n-word trademarks filed to prevent racist profits Chicago Tribune (2017)
Klan Barred from Playing Phone Tapes Courts: Judge rules the racist messages infringe on 'Mister Rogers' trademarks. Los Angeles Times (1990)