| 88618590 | O-K | Central National Gottesman Inc. | 6028887 |
| 78960901 | O & K | O & K Company, Ltd. | 3279952 |
| 71461856 | O.K. | OTTO L. KUEHN CO. | 0405441 |
| 71060025 | O.K. | O. K. MANUFACTURING COMPANY, THE | 0086323 |
| 74190420 | O'K | HUGH O'KANE ELECTRIC CO., INC. | 1710426 |
| 85792573 | O K | JIANGSU WELLCARE HOUSEHOLD ARTICLES CO., LTD. | 4419862 |
| 75639128 | O K | Propper Manufacturing Co., Inc. | 2331980 |
| 75320295 | O'K | HUGH O'KANE ELECTRIC CO., INC. | 2152621 |
| 77629655 | O K | Teng's Industrial Co. Ltd. | 3987573 |
| 76426111 | O&K | O&K Orenstein & Koppel AG | 2781410 |
| 85792572 | O K | JIANGSU WELLCARE HOUSEHOLD ARTICLES CO., LTD. | — |
| 75174473 | O.K. | Unilever N.V. | 2101435 |
| 74802713 | O.K. | O.K. Tire Stores Inc. | — |
| 74636174 | O&K | O&K ORENSTEIN & KOPPEL AKTIENGESELLSCHAFT | 1948962 |
| 74551821 | O.K | PCA INTERNATIONAL, INC. | — |
| 74525605 | O.K. | O.K. Tire Stores Inc. | — |
| 74433592 | O&K | O&K ORENSTEIN & KOPPEL AKTIENGESELLSCHAFT | 1842687 |
| 74349661 | O&K | O & K Company, Ltd. | 1820985 |
| 73804316 | O.K. | VISA U.S.A. INC. | 1576810 |
| 73264227 | O.K. | Aldriedge; Richard | 1242833 |
| 73100321 | O.K. | Visa U.S.A. Inc. | 1253927 |
| 72331763 | O.K. | KLEIN, OTTO | 0905868 |
| 71693916 | O.K. | OTTO L. KUEHN CO. | 0632383 |
| 71597495 | O-K | JAQUITH INDUSTRIES, INC. | 0546675 |
| 71593226 | O.K. | OTTO L. KUEHN C. | 0543073 |
| 71519214 | O K | OMICRON DELTA KAPPA SOCIETY, THE | 0440004 |
| 71141978 | O.K. | KENNAMETAL INC. | 0147320 |
| 71032442 | O. K. | Procter & Gamble Company, The | 0069573 |