Families of predicates can work together, and predicate relationships not used by a particular application are effectively invisible to it.
As the simplest possible example, compare visual markup and RDFa mixed together on the same XHTML page. A person looking at the web page is utilizing the visual markup, but would not see the non-visual RDFa markup. Likewise, one app might use location-centric relationships and not care about accompanying information. Another app might look at the same page and grab only the bibliographic connections. Domain-Specific Ontologies can work independently in this way, each with its own XSLT data extraction.