Thanks – yes, I saw that in the manual. Eventually I figured it out (heaven knows why it took me so long). Put “In” and “Out” in the “Change Case” exceptions list (in the title in question these are significant words, and they’re capitalized in the actual book title), and capitalize them in the EndNote library entry. It’s a bit of a kludge, because if for any reason you need sentence case in the headings you’ll have to uncapitalize them in the library entry, but it works. It would be nice if one had access to the rules that EndNote uses for capitalization, but it sounds from what you say that we don’t.
Thanks again for your help.