finally, an example

["D. J. Bernstein" <[e-mail]>]

> Suppose I
> send a message with "schaefer+party-4-july" in the From field local-part.
> Now I can filter the responses on "party-4-july".  But in order to do
> that, I had to know that "+" is a separator and "-" is not.

Apparently the sysadmin has told you that you can receive e-mail at
schaefer+*. So you type ``schaefer+party-4-july'' into your MUA.

If he says schaefer-*, you type ``schaefer-party-4-july'' instead.

Or, given appropriate MUA support, you type the ``schaefer+'' or
``schaefer-'' exactly once; then you type exactly the same
``party-4-july'' either way.

I don't see the inconvenience here. This all looks very straightforward.
How else would you expect this example to work?

> A specific example is not relevant.

Specific examples are everything. Thank you for providing one.

---Dan
Set up a new mailing list in a single command. http://pobox.com/~djb/ezmlm.html