On p. 68, I say the following:

Add specific inboxes: You can’t remove the global Inbox from the Sorter (or move it from its home in the upper-left corner), but you can drag the inbox from any of your other databases to the Sorter. Unfortunately, every Inbox has the same name and icon, so you can distinguish them only by position.

Several readers have pointed out to me that although you can't rename items in the Sorter, you can rename the Inbox in each database and then drag the renamed Inboxes to the Sorter, which will then reflect the actual name of each Inbox. Although I dislike this approach because I prefer to leave my Inbox named "Inbox," it is a way you can potentially tell one database's Inbox from another in the Sorter.

—Posted by Joe Kissell on May 5, 2010