So...Can i consider appdata_full struct is 8 interpolators?
(this seems to be reference to http://ask.fm/aras_pr/answers/141577610604 -- gosh ask.fm is terrible for discussions :))
"appdata*" structures in standard Unity shader includes are for vertex shader inputs. The vertex-to-fragment structures are typically named "v2f*". The interpolators/varyings talk is about the latter.