I almost typed "esoteric arcana" but that would be redundant.
Anyway, as of page 98:
epigraphical (P. 92): pertaining to the study of those quotes from other sources authors put at the beginning of books or chapters.
suzerain (P. 54): according to my sources, a feudal lord or baron, or a state "having some control of another state that is internally autonomous." I'm not sure the author uses this correctly. He refers to Andorra as a suzerain. Rather, I would think France or Spain would be the suzerain, having some element of control over largely independent Andorra. I had hoped to visit Andorra during my trip to Barcelona last summer, but the bus ride would have been too long. Next trip, however, in the footsteps of Richard Halliburton, I shall include Andorra on my itinerary.
oculus (P. 41): a round window. I kinda figured as much. Must be smaller than a rose window, though, huh?
gnomon (P. 41): knew that one; even tried to explain it to a group of 4th graders last week while we were looking at a sundial in the garden of Queen Emma's Summer Palace. Like they cared. And like any of them will ever read The Da Vinci Code, or anything else that uses the word gnomon. Although, I run across this word once or twice a year, including while visiting Kingston South East in South Australia, in which place I had the exciting opportunity to actually be a gnomon!
Plot-wise, I'm kinda not buying that all the cops at a very important and bizarre murder scene left the premises following a clever ruse by the protagonists. I mean, they all took off? Nobody was detailed to remain guarding the dead body sprawled in the middle of the Louvre, allowing "our heroes" to stop and chat about anagrams while making their getaway? Uh... no. Not buying it.
But the PHI stuff is cool. "PHI is a H of a lot cooler than Pi." I laughed muchly. I am such a geek.