| 100% | ENC | 3 | Bottom-of-letter abbr. |
| 100% | ENCL | 4 | Bottom-of-letter abbr. |
| 100% | ENCLS | 5 | Bottom-of-letter abbr. |
| 99% | ENC | 3 | Abbr. at the bottom of a letter |
| 99% | ENCL | 4 | Abbr. at the bottom of a letter |
| 98% | ENCL | 4 | Abbr. at the bottom of a business letter |
| 98% | ENCS | 4 | Abbr. at the bottom of a business letter |
| 98% | ENC | 3 | Abbr. at the bottom of a business letter |
| 98% | ENCL | 4 | Abbr. on the bottom of a business letter |
| 95% | POS | 3 | Getters of letters: Abbr. |
| 95% | GPO | 3 | Collector of letters: Abbr. |
| 87% | INIT | 4 | Letter of approval?: Abbr. |
| 86% | SOS | 3 | Letters of distress: Abbr. |
| 86% | ASAP | 4 | Letters of urgency: Abbr. |
| 82% | ENC | 3 | Abbreviation at the bottom of a business letter |
| 80% | MESSRS | 6 | Abbr. at the head of a letter |
| 80% | OMG | 3 | Letters of surprise, in text speak: Abbr. |
| 79% | KISSES | 6 | Smooches; the XXXs at the bottom of a love letter |
| 77% | OBO | 3 | Letters following the price of a used car: Abbr. |
| 77% | ENCS | 4 | Accompaniers of cover letters: Abbr. |
| 77% | APO | 3 | Receiver of private letters?: Abbr. |
| 76% | AET | 3 | Three letter abbr. sometimes seen on gravestones meaning "at the age of" |
| 76% | AKA | 3 | Letters between real and stage name of a celebrity: Abbr. |
| 76% | OBO | 3 | Letters following the price of a used car, maybe: Abbr. |
| 74% | TGIF | 4 | Joyful letters at the end of the week: Abbr. |
| 74% | PSS | 3 | Additions at the ends of letters (abbr.) |
| 73% | ENCL | 4 | Letter-bottom abbr. |
| 73% | USS | 3 | Letters at the start of an American navy vessel's name: Abbr. |
| 73% | ARR | 3 | What the last letter of 13-Across stands for: Abbr. |
| 73% | CAL | 3 | What the second letter of 17-Down stands for: Abbr. |