How soon can I post a duplicate of a book on my shelf that has been requested?  Does it have to be marked mailed?  Marked Received?  or what?

I am pretty sure it is after a book was marked mailed that you can post another copy.

Definitely can after the first one is marked mail as I've had duplicates in the past.

Thanks. I was headed out door to po and marked first one mailed so posted next copy......since it was on W,a it immediately came up as ready to print label so I quickly wrapped it and got both in mail at same time.  woo hoo........mailed out 7 books today!  It would usually take me 2 months to get orders for that many!

Yesterday I ordered 20 yo daughter 5 books/plays here needed for her college classes so was nice to put books in mail that will give me credits to make up for those orders.