| overlays lines to expunge reverse line feeds |
| and half line feeds (ESC-9 and ESC-8) |
| It normally emits only full line feeds; |
| (fine) allows half line feeds too. |
| removes backspaces, printing just one of each pile of overstruck |
| normally converts white space to tabs; |
| Other escaped characters and non-printing characters are ignored. |
| tbl file | nroff -ms | col | p |
| Format some tables for printing on typewriters; |
| to remove reverse line feeds, and |
| can't back up more than 128 lines or |
| handle more than 800 characters per line, |
| (013) as reverse line feed. |
