This one always seemed to me like a plausible alternative spelling (cf. traveler for traveller).
Maybe the reviewers who let this through were speakers of British English who knew it was misspelt but conceded it without a fight, having already lost on color, gray, center...
Re:Taming names in software development
by thaumasiotes on Sunday December 11, 2022 @01:09PM
(#33945655)
Traveler is stressed on the first syllable; referrer is not.
[0] https://annaken.github.io/a-brief-history-of-the-referer-hea...