[ih] Fwd: Reporter query on the history of greater-than in quoted replies

[Brian E Carpenter]

This page suggests to me that finding the earliest documentation of the Unix mbox format would be instructive:

https://www.freebsd.org/cgi/man.cgi?query=mbox&apropos=0&sektion=0&manpath=FreeBSD+Ports&format=html

Regards
   Brian