I downloaded 38784STD-BV9a.dtd from AF-TMSS, then noticed that when I open new and select the .dtd (I am using the latest Arbortext) a message appears "No Stylesheet Found". I know the style sheet extensions are .fos, .dcf, .style, and .xsl but none with those extensions exist in the unzipped files from AF-TMSS. Doesn't the DTD have the fos within or do you definitely have to add a stylesheet?
I downloaded the BV8a version and ran into the same problem. There was a .fos file but it was useless. I basically had to learn how to build a FOSI and create a new one for our project. I'm sorry that's not helpful, but that's what I ran into.
A DTD defines the structure of the document. It does not describe how it looks. A FOSI (.fos) is an Arbortext structure that defines how the data should be defined in Editing. If you are using the FOSI composer in Arbortext then the .fos file has data that describes how pages are to be built. If you do not have one from the AF web site, then you will have to build one to help n your editing. You really do not need one to create and edit a document, but it makes it much easier fro authors to work if thee is visualization of what they are creating or for what will be generated later by the styling program. Arbortext I believe is the only editor that uses a .fos (FOSI) as the language for formatting displays in their editor. Other editors have their own language. So unless you work with a military group that uses Arbortext themselves then you probably need to create this file.