Printing and Exporting Alternate Layouts
The Alternate Layouts feature in InDesign CS6 offers you the benefit of keeping several different versions of a document conveniently in one file. But it does make things a little more complicated when it comes time to specify a set of pages to print or export.
For example, what if you created a few alternate layouts in an InDesign file and you wanted to print just the first page of each alternate layout to compare them? In order to do this, you have to specify the pages you want with the name of the layout followed by a colon and then the page number. You separate each individual page with a comma (and optionally a space).
So if your document has two alternate layouts called iPad H and iPad V, and you want to print page 1 of each alternate layout, you enter in the Range field: iPad H:1,iPad V:1.
You can specify ranges within each alternate layout too. So if you wanted to print (or export to PDF) pages 1-2 of both layouts, enter iPad H:1-2,iPad V:1-2
You can also print a range of pages that spans more than one layout. So to print from page 1 of iPad H to page 2 of iPad V, enter iPad H:1-iPad V:2
When you're entering pages in the the Print or Export dialog boxes, spaces matter and so does case. So in this example, iPadH:1 won't work. Neither will ipad h:1, IPAD h:1, etc.
From my testing it appears that you can't use absolute page numbers when specifying alternate layouts for print or export. So if you wanted to print the second page of each layout (regardless of the actual page number), you'd have to enter the actual page numbers. iPad H:+2,iPad V:+2 doesn't work.