May 6th 2010, 21:09:29
Not saying anything about the current retal SoP in earth, but I recall being taught by PDM long before TAN was ever a member, that sending a retal message was not only polite, but also a requirement for its members.
Maybe a retal message has never been required to authenticate a retal, but the old PDM that I remember made damn sure that it was sent anyways.