the portion of ebxml most related to semantic transparency of xml exchange is the registry service, described in the draft registry information model and registry services specifications, which deal with the management and exchange of object-oriented entities . these registries aim at a higher architectural level than the international organization for standards basic semantic registry iso bsr, which i covered in my first column 4rdf允许在内存中管理这些模型(这也是到目前为止本系列中一直使用的方法),它也允许在持久存储(以平面文件的形式存储的诸如postgresql和oracle这样的sqldbms中,或存储在我所编写的实验性定制rdf后端mangrove中)中管理模型。