[…] the fundamental properties of Case-assignment are as in (1): (1) (i) NP is nominative if governed by AGR; (ii) NP is objective if governed by V with the subcategorization feature: −NP (i.e., transitive); (iii) NP is oblique if governed by P; (iv) NP is genitive in [NP − X-bar]; (v) NP is inherently Case-marked as determined by properties of its [−N] governor. Let us refer to the case assigned under [...] (v) as "inherent Case" [...] Inherent Case is presumably closely linked to θ-role.
- Chomsky (1993), a pag.170-171

[…] "inherent Case", including now the Case assigned by prepositions, is assigned at D-structure.
- Chomsky (1993), a pag.292