"3.7 Replacing Blank Nodes with IRIs" very misleading

[franconi]

Section 3.7 Replacing Blank Nodes with IRIs states:
systems MAY systematically replace some or all of the blank nodes in an RDF graph with IRIs. Systems wishing to do this SHOULD mint a new, globally unique IRI (a Skolem IRI) for each blank node so replaced.
and it goes on making a very misleading statement:
This transformation does not appreciably change the meaning of an RDF graph, provided that the Skolem IRIs do not occur anywhere else.
In general this is not true, and its application has to be understood deeply. This statement has already created damages in the definition of SPARQL OWL entailment regime.
As an example, consider the following valid entailment:
:a :b _:x. ⊨ :a :b _:y.
By naïvely applying the above skolemisation process, we get that:
:a :b :sk-x. ⊭ :a :b :sk-y.
I don't see how the applicability conditions of skolemisation could be easily explained without using heavy logic machinery.
I also don't see why there should be such a Section in RDF-Concepts.
I propose to just kill Section 3.7.