Which and closest preceding "main" noun

[jonathanb875]

Hi,

In a lot of problems' solutions, I see that "which" must refer to the closest preceding main noun. Is there other kind of nouns ? (other than "main" nouns). Are nouns that appear in prepositionnal phrases considerered "main nouns" ?

Thanks a lot !

[RonPurewal]

i have no idea what a "main noun" is.

"which" modifiers have been used only in 2 ways by GMAC:
usage-of-which-t746-15.html#p104933