Halliday & Matthiessen (1999: 209):
… the nominal group is organised as a move along two semantic dimensions: the elements become increasingly stable in time, and increasingly complex in their taxonomy of features. Lexicogrammatically, this corresponds to a move from grammatical items (determiners, determinative adjectives such as usual, same, typical, cardinal and ordinal numerals) to lexical items (adjectives [in general], and nouns); that is, a move from closed systems to open sets.