Speaking of dragging addresses between books, I don't know if this is the case for Windows users, but in NS7.02 Macintosh, OS 9.2, there is no visual confirmation of this action other than that it shows up in the destination address book.
What I mean is, you drag the address to the icon for the destination book, but the book's icon doesn't darken, highlight, flash, or whatever. It looks like nothing has happened, but lo and behold, when you check the destination book, the copied address is there.
Yet another of several annoying cosmetic interface inadequacies (the others? just ask me ... I'd be happy to rant) in Netscape 7.02. At least on a Mac in OS 9.2.
Frederick
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