Messages that you've deselected are no longer marked by a '>'.
The deselections are also cumulative. You can select and deselect as much as
you want. Knock yourself out.
Once you've selected some messages, additional commands become available:
[O] Opposite selection toggle.
[Z] Zoom toggle.
After you've selected messages, you may decide to deselect some of them.
You can do this by entering a period, followed by the minus sign, and then
the message sequence numbers(s) in any of the following ways:
.-n DeSelect one message. For example: .-5
.-n-m,a,c-d DeSelect several messages. For example: .-1,5 or .-1-3,5,8-10
.-n- DeSelect all messages from this one onward. For example: .-6-
.-* DeSelect all of the messages in the list.