Excerpt from a letter written by R.A.B. Mynors, quoted in Wendell Clausen, "Sir Roger Aubrey Baskerville Mynors: 28 July 1903, Wiltshire, England, 17 October 1989, Hereford, England," Vergilius
35 (1989) 3-7 (at 6):
My ideal commentary on a Latin author would quote exclusively
from Latin Greek and English authors (other tongues if I knew
enough) and never mention a modern author (other than Pauly
Wissowa and Thes.) except where one has an obligation to acknowledge — grossly unprofessional conduct.