Since microformats typically don’t try to solve specific cases for niche fields, RDFa picks up where microformats leave off by adding an open-ended mechanism for extending the semantics of markup without limitations from the host markup language itself. In other words, RDFa is a simple and, more important, language-agnostic way of giving documents the means to be self-describing. RDFa uses a set of attributes (hence the trailing “a”) that can be attached to any element whose values reference other elements in the same or other documents