Examples:
Obtaining an Notation3 format class
RDF::Format.for(:json) RDF::Format.for(:ld) RDF::Format.for("etc/foaf.json")
RDF::Format.for("etc/foaf.ld")
RDF::Format.for(:file_name => "etc/foaf.json")
RDF::Format.for(:file_name => "etc/foaf.ld")
RDF::Format.for(:file_extension => "json")
RDF::Format.for(:file_extension => "ld")
RDF::Format.for(:content_type => "application/json")
Obtaining serialization format MIME types
RDF::Format.content_types
Obtaining serialization format file extension mappings
RDF::Format.file_extensions