The articles such as the one you mention are sometimes research papers, and all the features mentioned in such papers do not necessarily make it into the product. The documentation and technical white papers (which are marked as Oracle white papers) should be considered as documents that accurately reflect the functionality in the product.

That said, the documentation could have been clearer in explaining what is done with respect to reification. The scheme proposed in the research paper you mention is not supported, and hence IS_REIFIED_QUAD is not supported (yes, the description in the documentation is inconsistent and we are fixing that in the next release). However, an application can reify a statement and store that, the internal optimization of storage will optimize the storage of the reified statement to the extent possible. There is no restriction to an application reifying a statement and storing that.

We apologize for any confusion and consequent inconvenience.

Melli