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 |
|---|---|---|
| Lucas | 2 | 1490 (courtasy); 1507 (bastardry) |
| Louk | 1 | 1560 (clerk) |