Requirements have no effect on meaning.

Concepts are unaffected by whether or not you choose to include them in an application.

If a given concept is that of a relative thing then that is the only thing it can mean; if you need to stand it up in an ontology at all, you need to model it according to its meaning.

Meaning is not negotiable; whether you include it in a given application is.

Ontology is not about deciding how to model something, it is about recognizing what something means, and modeling that.

Ontology is an exercise in detection not creation.

The Art of Ontology is the Art of not designing something.