The following information is taken from the Dictionary of the Older Scottish Tongue, available online at http://www.dsl.ac.uk/index.html. This is a work in progress.
| Spelling | Number | Dates & headers |
|---|---|---|
| Douglas | 3 | 1386 (betwene); 1418 (borch); 1545 (awake) |
| Dowglas | 3 | 1446 (barounry); 1455 (complice); 1572 (bard grote) |