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 |
|---|---|---|
| Bule | 1 | 1462 (annual) |
| Bull | 1 | 1617 (bedding) |
| Bulle | 1 | 1462 (ake-tre) |