The values of this feature allow one to distinguish between preposition and postposition. MULTILEX also has a value for circumposition.
In NERC, GENELEX and AlethDic, Prepositions constitute a separate category without any attribute at the morphosyntactic level; in GENELEX, the distinction, based on a semantic classification between temporal, manner and place is foreseen at the syntactic level.
In NERC, Prepositions also include Particles. In English, there is a problem of distinguishing the verb particles from prepositions, but many tagsets provide a separate label for particles.