As a GM, when I put a private line to multiple recipients in a post, there are "include" and "exclude" checkboxes.  I understand the include -- if a person isn't included, they're excluded.  Why the exclude?  If I didn't include them aren't they automagically excluded from reading a private line, even if I didn't explicitly check that?

If someone is under a curse that alters their appearance to observers, but not themselves, that could be used to specifically exclude them from informing others what the curse makes them look like.

That or just about any other detail you might want to exclude from an individual.
This message was last edited by the user at 02:09, Tue 22 Apr 2014.

"Private to not Genghis the PC" will show a private line to everyone in the game except to you.  Much easier than specifying everyone in the game.

You can also do combinations "Private to group in the bar; not Genghis the PC".  Again, if you've got a group set for a location (or whatever) and you want to send them all a message but exclude someone who's in the group (maybe the PL is about them?) then it's easier this way.

Can also be used to devastating effect with Secret to lines.  (c;  "Secret to not Genghis the PC:  It's true!  Secret to Genghis the PC:  It's a lie".  You're going to see the opposite to everyone else.

Hmm, nice, so a GM can basically lie in private messages and make people think they're seeing the same private message as everyone else when really they're seeing something completely different.  Thanks, this is going to be fun. :)

Precisely.   Secret is fantastic for it because unlike a Private line the players never even think the GM is being sneaky.  With Private, the player is alerted that only they or a select group are reading it.  With Secret, the text appears the same as regular written text, so the players are blissfully unaware that anything is even remotely different.

It can lead to wonderfully exciting dialogue confrontations as PCs who experience the same event through different glasses try to figure out just who is correct.