PROPERTYs cannot be fillers of other slots in EVENTs or OBJECTs in the ontology for the following reason: we will not have instances of PROPERTY concepts under normal conditions to fill the slots. For the purpose of constraining or relaxing possible fillers of a slot, only OBJECTs and EVENTs can be used in the Sem facet (and Default facet, etc.) in the ontology. If we want to allow reified PROPERTYs to be fillers of slots in a lexicon or TMR, we indicate this in the ontology by not having any constraint at all on the slot (i.e., by making the Sem ALL).
For example, to represent the ``specify a need'' sense of the Spanish verb ``precisar,'' we cannot use the EVENT SPECIFY and constrain its THEME to (Sem PRECONDITION) since the filler must then be a PRECONDITION RELATION. Nor can we create a child of SPECIFY in the ontology whose THEME is constrained to be a PRECONDITION. This meaning involves a semantic reification and it must be represented in the lexicon by reifying a PRECONDITION RELATION and using the reified frame to fill the theme slot of SPECIFY.