RFC 1925, "The Twelve Networking Truths", April 1996

Errata ID: 4939
Status: Rejected
Type: Technical
Publication Format(s) : TEXT
Reported By: T Rogers
Date Reported: 2017-02-17
Rejected by: John Scudder
Date Rejected: 2024-02-11

Section 2 says:

No matter how hard you push and no matter what the priority,
        you can't increase the speed of light.

It should say:

No matter how hard you push and no matter what the priority, 
you can't increase the speed of light. You can, however, 
slow it down.

Notes:

Light travels more slowly through media such as glass, and the speed depends on frequency - this is how refraction works.
--VERIFIER NOTES--
The erratum would have been correct if the original text had said “speed of light in vacuum“, or its synonym, “c”. But it didn’t, so as far as I can see it’s correct, and consistent with the observations made in the notes that were submitted.

Report New Errata