I'm working on a book (laid out in DocBook and rendered to pdf with RenderX's xep). The book addresses a medical condition named DSD. There are many sections containing "DSD", and it is frequently plural.
What's the correct way to set the plural of an initialism when it occurs in an all caps context? For instance, "DSDs AND TIMING OF SURGERY"? If this is typographically correct, I'll have quite a struggle to convince the software to give special treatment to the final "s" in DSDs.