It seems a simple enough matter to extract a general principle of subcategorisation out of (81), along the lines of:

(82) SUBCATEGORISATION PRINCIPLE

(82) Any lexical item of category X will be subcategorised with respect

(82) to the range of idiosyncratic Complements (i.e. sister constituents)

(82) which it permits within the (minimal) X-bar containing it

The subcategorisation frame for X will simply be an unordered list of the sets of categories which X permits as its Complements: we assume that the relative ordering of X and its Complements will be determined by independent principles (e.g. the HEAD FIRST PRINCIPLE).