The following information is taken from the Dictionary of the Older Scots Tongue, available online at http://www.dsl.ac.uk/index.html. This is a work in progress.
| Spelling | Number | Dates & headers |
|---|---|---|
| Duff | 3 | 1493 (cautioun); 1617-8 (cationar) |
| Duffes | 1 | 1636 (crepill) |