Dieter Maurer wrote:

(...) What does "mandatory" mean? Rejected by Ken, if it is missing? Hope not ...

Not at all. Mandatory keys are a commom practice in some very busy lists I've been at before. The spirit is "if you are unsure about what key to choose, use GEN: for generic stuff (or something like that); but if you don't use any at all that means you don't want to be kind to every other subscriber" (if you didn't forget it when you posted it). That would also mean, "if you want to be paid attention, use them".

Many posts here are from newcomers. Let them a chance to get acquainted with the list and its nettiquettes.

Dieter

From a newbie perspective, it is also helpul: the use of proper keys would help newcomers to associate certain new terms contained within a mail's subject, to the key (and the topic) it is supossed to belong, without having to read it (while at the firsts steps of the learning curve). Anyhow, the most common use would be to filter the messages, in order to save or discard them. The downside of not to prevent the potencial problem, as I've seen at other crowded lists, is the loose of interest in it by their senior users, and a feeling of infinite freedom of the non-serious newcommers.

After all, as I said, this is just an idea. Greetings, Ausum