Others have written about the deep layers of The Name of the Rose (enjoyable as a murder mystery on the surface, with allegory lurking in the depths).
I'll just add that Umberto Eco used symbols and layers even for his characters' names and appearances.
It's easy to lift the masks of (at least) two of the characters:
William of Baskerville is Sherlock Holmes
- Their adventures are chronicled in first person by their assistants.
- Holmes is a cocaine addict, William chews some unspecified herbs "good for an old Franciscan, but not for a young Benedictine".
- Both detectives can describe in detail a scene that they've never seen, relying only on logic deductions.
- Holmes solved the famous case of The Hound of the Baskervilles.
- They are both native English speakers.
Jorge of Burgos is Jorge L. Borges
- They are blind.
- Jorge of Burgos was a librarian with a gift for tongues; Borges wrote the famous short story "The library of Babel".
- Jorge of Burgos is the keeper of a labyrinthine library with mirrors in some of the rooms; mazes and mirrors feature prominently in Borges' works.
- Their names sound similar.
- They are both native Spanish speakers.
Eco also had some plain old fun with the names:
- The monk that betrays his closest friend is Salvatore, a name that in Italian means "Saviour".
- One of the old abbots is Roberto of Bobbio, a nod to the (late) Italian philosopher Norberto Bobbio.
- The original name of the narrator is "Adso da Melk". Grab your closest Italian-speaking friend and
make him say that ten times fast; the name will morph into an obscene suggestion. Ok, it's just my dirty mind.
Mr. Eco is a respected writer and professor, and these are childish jokes. Naughty Vorbis, naughty...