What this record means
The record shows that “FUN” was registered on the Principal Register to S. John Byington on April 21, 1981, but the registration was cancelled on October 21, 1987 because the owner failed to file a proper Section 8 declaration, so the mark is now dead. The only listed goods are “Magazine Pertaining to Toys, Games and a Variety of Diversions” in International Class 016, which means the closest area of concern is any magazine or printed publication that covers toys, games or similar leisure topics. The record does not give the owner control over every use of the word “FUN” in other product categories or services. The prosecution history shows a correction under Section 7 in 1982 and the final cancellation in 1987, with no later maintenance filings. The supplied history contains no oppositions, cancellations by a third party, or court actions, so there are no visible enforcement signals. I'd treat this as a modest concern if you plan a magazine about toys or games, but the risk drops sharply for unrelated goods.
Informational only - not legal advice.