and yes, I did search first but I couldnt find it

anyway, sometime i receive PM from members complaining etc etc, and sometime I receive message telling me that a certain member is using multip nickname. Anyway the point is, when I reply to these message I want to be able to copy it to my other admins or moderators or even a certain member so I can keep them in a loop.

Is there a modfiication for this, if not, is anyone interested in making this one, I think its very useful

I think that could be useful too, and I don't think anyone has done that yet.

Should it work like an email CC, where each recipient can see who the other recipients are, or like a BCC? Or should both options be available?

P.S.

There was a suggestion a long time ago to change private messages to private threads, to which any number of users could be "invited".

It would be nice, yes. I'd say both BCC and CC, but if only one, it should be CC.

That "Private threads" suggestion was also very interesting, yes...

I like BCC personally