J. David Bryan wrote:
In any case, this will *not* change the settings for all who are subscribed already (because we can't tell who explicitly wants them off).
Given that posts from current subscribers will not be prefixed, unless each subscriber changes his or her preference, prefix filtering will always be unreliable.
No, the settings go by recipient, not sender. (Of course, quotes from a user who's set the prefix will have the prefix as well, so those who haven't set the prefix will get such quoted prefixes as well, but those who have set the prefix option should always get one.)
Frank