The Q&A here has been very helpful in finding my own blind spots. I seem to still have one lingering out there, though. Of the 20 final validators, I am stuck on #4 "Simple string of characters which must not be modified".
If the "simple string" contains a newline character (which must not be modified), how is it to be presented? It seems that if it is part of a block, text after the newline should also be indented. But then that modifies the simple string.
I have tried both indenting and not indenting text after a newline buried in a "simple string", and neither case is liked by the #4 validator. Of course, perhaps text inside a pair of quotes with a newline in between would no longer be "simple". But I can't figure out why the heck this simple case, of all others, fails.