This is probably going too far off topic here, but ...
"The Wicker Man" has been minutely analyzed to the extent that every filming site has been photographed and documented and every line and reference analyzed and explained.
While Suspiria has its legions of followers, I haven't found that this film has received quite the same analysis, although it has been analyzed in terms of the filming techniques and stylistic form (which, on the other hand, I haven't seen for Wicker Man). (And Eye of the Devil, which is my personal favorite, has not received either sort of in-depth study to my knowledge.)
For example, I wondered if anyone has translated the Latin or Hebrew words that appear in gold lettering along the walls leading up to the sanctuary. (I've had one semester of Latin so I suppose I could do this myself if I had the time ... )
Does anyone know exactly what is going on when Joan Bennett's character is being served in a ritual that appears to possibly be a "black mass"? I'm not sure just what a black mass is, but in this scene she seems to be served a type of "communion."
I'm reading a book I recently obtained from a small press in England on old Finnish magical practices and the author refers briefly to a black mass where a slice of turnip dyed black is served. (I'm not certain in this instance if the author is referring to an English ritual as the writing is a bit unclear.)