Help talk:Style conventions
I rewrote a little and trimmed
"An exception to this [title as text] rule occurs when the verifiable original source text of the work (not the title of the text work) uses different capitalization, and in cases of doubt, the above convention should be followed. "
I think it merely notes that there may be different sentence capitalization styles and that it is ok to adopt an author's original His or Thy.
There is a glaring set of cases where we haven't made up our minds which paragraph applies:
- Cantata BWV 39 - Brich dem Hungrigen dein Brot (Johann Sebastian Bach) rather than
- Brich dem Hungrigen dein Brot, BWV 39 (Johann Sebastian Bach)