| Prefix | Suffix | Definition |
| . | 1 | BACK-TO-BACK DUPLEX |
| . | 2 | FACE-TO-FACE DUPLEX |
| . | 3 | TANDEM DUPLEX |
| . | 4 | UNIVERSAL DUPLEX |
| . | B | RELIEVED LAND ON INNER OR OUTER RING. DIGITS ADDED TO INDICATE DESIGN OF RINGS AND TYPE OF RETAINER INCLUDING PHENOLIC PLASTIC |
| . | C | CHANGE FROM STANDARD DIMENSIONS |
| . | D | RIBBON RETAINER (USED ONLY WHEN BOTH CROWN OR RIBBON AVAILABLE FOR A GIVEN SIZE |
| . | EE | EXTENDED INNER RING |
| . | G | GROOVED OUTER RING |
| . | H | WITH THROUGH-HOLE (PIVOT TYPES) |
| . | K | RADIAL PLAY-FOLLOWED BY EITHER TWO OR THREE DIGITS FOR EXAMPLE: K13 RADIAL PLAY OF 0.0001 - 0.0003 K811 RADIAL PLAY OF 0.0008 - 0.0011 |
| . | L3 | ONE SEAL - GLASS REINFORCED TEFLON. TO INDICATE 2 SEALS USE LL3. |
| . | L4 | ONE SEAL - GLASS REINFORCED TEFLON WITH STAINLESS STEEL INSERT. TO DESIGNATE 2 SEALS USE LL4 . |
| . | L5 | ONE SEAL - SYNTHETIC RUBBER WITH INTEGRAL STAINLESS STEEL INSERT. TO DESIGNATE 2 SEALS USE LL5. |
| . | M | METRIC DIMENSIONS |
| . | P | ONE SHIELD |
| . | P2 | SHIELD ON SIDE OPPOSITE FLANGE |
| . | PI | SHIELD ON FLANGE SIDE |
| . | PP | TWO SHIELDS |
| . | T | PHENOLIC CROWN RETAINER. DIGITS ADDED TO DENOTE MATERIALS OTHER THAN PHENOLIC |
| . | UP | NARROW WIDTH-SINGLE SHIELD ONLY |
| . | W | LOW TORQUE |
| . | Z | SPRING SEPARATORS |
| F | . | FLANGED BEARINGS |
| N | . | BERYLLIUM COPPER |
| R | . | RETAINER RADIAL |
| S | . | STAINLESS STEEL |
