View > Master Pages
Navigate to page MasterPageMaps
Then do: Format > Page Layout > Apply Master Pages (AMP)
This creates the page and an empty UnstructMasterPageMaps table.
Designate a paragraph format (aka tag or style) that is unique to the rotated page content, such as Body.Rotated, which may wel be identical to Body in all but name.
Assuming your rotated MPs are named Left.Rotated and Right.Rotated, fill out the UnstructMasterPageMaps table, such as:
Tag Name Right-Handed Left-Handed Range Indicator Comment Body.Rotated Right.Rotated Left.Rotated Until Changed Triggers landscape Body Right Left Until Changed Resumes portrait
Optimal trigger/resume tags are highly dependent on document structure and may require some experimentation.
Once set up, you need to do a manual AMP operation for initial MP assignment, and periodically as re-flow occurs. You can do this as above, or from the Book menu (it's an Update Book option)
I've tried the automatic rotating of the pages, but up to now I couldn't make it working.
Maybe there is a problem, as I startet the work on a german trail version. When I was allowed to buy the software, I've bought the english version. On the reference page, there are now some things in english and some in german. For the Unstructured Masterpage Map, there is even the table in german and english existing. I don't know if on table could be deleted or not.
I've tested now the table UnstructMasterPageMaps in an empty file. First I couldn't make it work, until I've found out, that I have to execute Apply Master Page after assigning the specific style.
Just a note about abreviations: for me it wasn't always shure, what the used abreviations ment. I could easely guess MP. For AMP I had already more problems.
Thanks now its working.