After struggling a couple of weeks with FM, it occurred to me (belatedly) to see if there's a book that might give insight into FM's user interface.... Amazon & Kindle to the rescue - Matt Sullivan and Rick Quatro's FrameMaker Creating and Editing Content.
This was after checking out the materials on the Adobe site (my review, should it ever happen, will begin, "This uneven, eclectic collection of uncategorized materials...") and attacking the help file. Unfortunately, the help file kept attacking back and for the first time, I could get nowhere.
Thanks to Matt and Rick, I now have a resource that rewards my searches. At last, for example, I discovered
the reasons behind the hilarious results of my attempts to insert and otherwise futz with a table
how to unravel exactly what a given T could possibly mean