Prepositional phrases are of type pp and are headed by prepositions, i.e. elements of type p. Prepositions subcategorize (usually) for an NP, so the value of SC on P will be a list of length one, containing the NP-complement. The feature PFORM takes as value the specific form of the preposition heading the PP (i.e. van, op, naar, ...). This information can be used to let a verb select a PP headed by a specific preposition.
Full PPs can modify nouns or verb phrases. Therefore, PP has a feature MOD. MOD has to be present on P as well, as the relation between the semantics of the preposition and the element it modifies is encoded as part of the lexical entry of a preposition. Here, we give the rule which forms PPs and the rule which lets a PP combine as a modifier with a noun.
It should be noted that since adjectives precede the nouns they modify and PPs follow them, an expression such as volgende intercity uit Groningen (next intercity from Groningen) will receive two parses. This appears to be a case of spurious ambiguity. There are intensional adjectives, such as zogenaamde ( alleged), which need to be able to take scope over a complex noun, but it seems that modifying PPs never need to take scope over a adjective + noun combination. It is not easy to rule out the latter type of derivation, however, without introducing additional features.