Karl T. Ondersma
Karl T. Ondersma is a USPTO correspondent of record based in Grand Rapids, MICHIGAN, listed on 416 trademark filings (313 currently live). The correspondent has worked across 121 distinct trademark owners — a mid-breadth client roster at roughly 3.4 marks per client. In TTAB matters, 135 proceedings appear on the record, more often as plaintiff (112) than defendant (23). The correspondent is associated with Gardner, Linn, Burkhart & Ondersma LLP.
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Editorial deep dives on prosecution strategy, TTAB, and brand portfolios
TTAB Q4 2025: Opposition Plaintiffs Won Roughly Five of Every Eight Decisions
When the Trademark Trial and Appeal Board cleared its opposition docket in Q4 2025, the people who filed the oppositions mostly walked away winners.
Maradona's Heirs Win at the TTAB as Q1 Filings Slip 7.4%
On the last day of the quarter, the Trademark Trial and Appeal Board sustained an opposition brought by the heirs of Diego Armando Maradona against Sattvica S.A.
Challengers Won Most TTAB Oppositions in Q3 2025 — and Big Tech Filed a Late-September Wall of Them
When the Trademark Trial and Appeal Board decided an opposition on the merits this quarter, the party bringing the challenge usually won.