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 |
|---|---|---|
| Irwin | 2 | 1471 (convocatioun); 1478 (chefe) |
| off Erwyne | 1 | 1438 (by-stand) |
| of Iruyne | 1 | 1511 (cors) |
| Irwyne | 1 | 1566 (complece) |
| of Irwyne | 1 | 1388 (betwixt) |
| Irwyng | 1 | 1550 (commit) |