The lexicon is a set of lexical elements, each an articulated system of features. It must specify, for each such element, the phonetic, semantic, and syntactic properties that are idiosyncratic to it, but nothing more.
- Chomsky (1995), Pag. 130

The lexicon specifies the elements that CS selects and integrates to form linguistic expressions - (PF, LF) pairings, we assume. The lexicon should provide just the information that is required for CS, without redundancy and in some optimal form, excluding whatever is predictable by principles of UG or properties of the language in question.
- Chomsky (1995), Pag. 6